2001 Acura MDX Press Kit

2001 Acura MDX - Overview

INTRODUCTION
The 2001 Acura MDX' was created to define a new era in the evolution of luxury class sport utility vehicles, treading beyond the limits of existing SUVs in terms of handling, packaging efficiency and environmental impact. Both models of the newest Acura &endash; MDX and MDX with Touring Package, were developed with an over-riding goal of setting new benchmarks for luxury SUV performance. That performance goal applies to the three main themes of the development concept, to establish new performance benchmarks in the SUV category for versatility, responsibility and dynamic performance. An additional development goal was added as its need was realized -- the MDX development team sought to provide features that effectively "defeat winter" for its driver and passengers -- limiting the harsh effects of the cold winter months on MDX occupants.

These goals encompass all areas of development, even when they are seemingly at odds with each other. For example, the Acura MDX is powered by a 240-horsepower 3.5-liter V6 engine -- more performance than any 6-cylinder SUV in its class -- yet it is also offered as an ultra-low emissions vehicle (ULEV) in all 50 U.S. states. MDX also manages to achieve an impressive EPA estimated fuel economy rating of 23 miles per gallon on the highway. In a similar manner, MDX's stylishly sculpted exterior belies the spacious and versatile interior -- boasting the only 7-passenger seating of any SUV in its class, and any number of easily configured seating/cargo layouts. And the confident on- and off-road performance of MDX does not detract from its thorough active and passive safety systems.

The MDX was created to be the best luxury class SUV, designed to live up to its designation as a Multi-Dimensional Cross Trainer -- an athlete that excels on many playing fields.

PERFORMANCE ATTRIBUTES OVERVIEW
Outstanding performance has always been a fundamental Acura character trait. The development of its first in-house designed and engineered SUV presented the opportunity for the MDX's engineers to sidestep the standard shortcomings of products already on the market and begin with a fresh approach to the SUV equation. That was achieved by setting out to create the first no-compromise SUV -- melding attractive design, unmatched versatility, driving exhilaration, social responsibility, and value in one neatly wrapped package.

To venture beyond established SUV performance boundaries, MDX introduces several new technologies. Its 3.5-liter V-6 engine is tuned to deliver an outstanding 240 peak horsepower at 5300 rpm with 95-percent of its peak torque (245 lbs-ft) available from 2000 to 5500 rpm. MDX also rates ULEV emissions certification for the entire 50 states of the U.S., and it also scores higher in EPA mileage tests than any other six-cylinder, 4x4 SUV. In the interests of helping provide sure-footed all-weather traction and exemplary medium-duty off-road prowess, the engineers invented an entirely new and exclusive Variable Torque Management (VTM-4) 4-wheel-drive system that's notably more compact and smarter in operation than the hardware found in competitor's models.

Acknowledging that ordinary SUVs feel clumsy and cumbersome, extra effort was invested in making sure that the MDX provides driving exhilaration consistent with Acura standards. Chassis systems and the power-to-weight ratio are optimized with balanced all-around performance as the priority.

MDX's 3500-pound tow rating with towing package (4500-pound for boats) was achieved by tuning the powertrain and chassis systems to manage heavy loads with confidence. This vehicle's wider-than-normal stance, high-torque engine, a close-ratio 5-speed automatic transmission that has a broad range of operation, and powerful brakes yield a highly competent tow vehicle.

ACCELERATION, BRAKING, CORNERING PERFORMANCE
A pillar of the Acura development approach is that the driver's seat should be the most rewarding seat in the vehicle. With this in mind, the development team groomed MDX to behave like a sport sedan when driven in an assertive manner. The starting point is a new 3.5-liter SOHC V-6 engine that seemingly achieves the impossible by combining remarkably broad range of torque -- 245 lbs-ft from 3000 to 5000 rpm -- with a potent 240 horsepower at 5300 rpm. Factor in a wide-ratio five-speed automatic and a sensible curb weight achieved by the shrewd use of high-strength materials, and MDX posts best-in-class acceleration performance. The sprint from zero to 60 mph requires less than nine seconds. Thanks in part to its best-in-class aerodynamic drag coefficient, MDX sprints through the quarter-mile in less than 17 seconds and trims 1.3 to 2.3 seconds from the Mercedes-Benz ML 320's passing times.

Demanding drivers expect a braking system to match a vehicle's acceleration &endash; and MDX measures up to that task as well. To provide short stopping distances, high fade resistance, and a reassuring pedal feel, the MDX's four-wheel disc braking system uses large-diameter rotors and extra-rigid single-piston calipers. The Anti-Lock Braking system (ABS) features electronic distribution of brake forces for optimum use of the traction available at each corner of the vehicle. The result is best-in-class braking performance for short stopping distances with a confident pedal feel.

Excellent handling begins with getting the fundamentals of vehicle dynamics right from the start as well. A wide track maximizes stability and cornering grip so MDX has the widest track in its class. The MDX design was tuned to achieve the best possible maneuverability and helps to minimize the cumbersome feeling that plagues most truck-based SUVs.

To overcome the usual ride-versus-handling compromises, engineers incorporated front and rear subframes to isolate road noise and driveline vibration from the passenger compartment, along with independent front and rear suspension systems with extra wheel travel and complementary suspension geometry. Low roll centers are combined with stiff anti-roll bars to provide progressive, predictable cornering response and excellent stability at the limit of adhesion. Lightweight materials &endash; such as aluminum castings for all major driveline components and extensive use of high-strength-steel unit body components -- give MDX an overall agile feeling.

THE VERSATILE SUV
The multi-dimensional theme of versatility was applied to each area of development, from exterior and interior styling to powertrain to chassis design and the many performance targets. From the inside out, MDX offers many options to the driver and passengers. Starting with the potential of six seating positions from the split and folding second and third-row seats the MDX offers the most passenger/cargo combinations in the mid-size luxury SUV class.

The options don't end there however, as the powertrain is tuned for optimum performance in virtually any condition the driver is likely to encounter. Key to this is an engine that is powerful, fuel efficient and environmentally cleaner -- with a broad range of torque and horsepower. Likewise, the 5-speed transmission offers one of the widest overall gear ratio ranges in the segment, ensuring that engine speeds are matched as closely as possible to the demands of the driving conditions at any time.

For the interior and drivetrain adaptability to be meaningful it has to be coordinated with a platform and chassis components that are equally well-suited to any possible conditions. MDX's unit body construction provides the optimum balance of strength and rigidity while still being the most space and weight efficient construction for an SUV of this size. All suspension, steering and braking components are designed to minimize unsprung weight to avoid adverse effects on handling, but are still rugged enough for medium-duty off-road driving.

THE RESPONSIBLE SUV
MDX demonstrates a high degree of environmental responsibility by providing excellent fuel economy with very low exhaust emissions. MDX is the first SUV to achieve stringent ULEV emissions levels for all 50 states -- thanks in part to a low-thermal-mass exhaust system that helps the three-way catalytic converter heat-up to full effectiveness quickly after a cold start. The MDX's combination of 17 mpg city and 23 mpg in EPA highway tests places it well ahead of ordinary mid-size SUV fuel economy and stands out as an exception to the trend that powerful SUVs cannot also be environmentally responsible and fuel efficient.

Safety has been an integral part of the MDX design from its inception, and an important aspect of the responsible SUV concept. To help avoid situations that could lead to a collision, MDX is engineered with the agility and maneuverability necessary to maintain control in emergency maneuvers.

When a collision is unavoidable, MDX helps protect its occupants with a reinforced body structure and state-of-the-art occupant protection features.

MEDIUM-DUTY OFF-ROAD CAPABILITY
The engineers who designed the MDX tested a range of competitive SUVs to help quantify off-pavement use patterns, customer needs, and engineering targets for the new MDX. Nine off-road parks in California, Nevada, Kentucky, North Carolina, and Michigan were visited to study SUVs in their natural off-road habitat. While a few competitors offer the extra ground clearance, driveline equipment, and chassis hardware necessary to support ambitious excursions off-roads, the engineers learned that few customers use these extreme capabilities regularly. Accommodating extreme off-road use would impose unreasonable compromises elsewhere in the vehicle, such as added weight, awkward entry and egress, poor fuel economy, and reduced dry-pavement performance.

The conclusion was that surpassing the class's most capable off-road machine was not in MDX's best interests. Instead, a more realistic goal was established. After observing casual off-roaders, MDX engineers concluded that a medium-duty off-road capability was most consistent with the philosophy embraced by the MDX. Medium-duty capability would readily support trips into the wilderness for camping or to launch a boat without providing the rigorous equipment needed to conquer the Rubicon Trail.

To define exactly what constitutes medium-duty off-road capability, the MDX engineering team selected 14 key performance criteria based on observations of casual off-road adventurers. They then constructed special test courses at their R&D facilities in North America to assure that MDX delivers all the intended capabilities with impeccable reliability and durability.

The list of test courses includes:

• 30-degree dirt hill
• Sand hill
• Water pit
• Rock roads
• Embedded log course
• Step-up, step-down
• Sand drag strip
• Gully course
• Ground contact course
• Washboard road
• Frame twister
• Power hop hill (23-degree slope with rippled surface)
• Gravel road
• Startable grade

Numerous engineering changes were based on experiences gained in testing. A deeper oil pan was included to meet the hill climbing criteria. A more effective air filter was specified to remove dust from the engine's air supply. The tow hooks were upgraded to handle loads imposed during extraction from stuck vehicle situations. Waterproofing was added to support MDX's ability to traverse up to18-inch-deep bodies of water. Throttle linkage was calibrated to provide more sensitive control over engine output at low speeds and improved start-up feel.

For an acid test, engineers took prototype vehicles for a 200-mile off road test on the Mojave Trail located in Southern California. This gauntlet of loose rocks, sandy washes, twisting grades, and narrow escarpments helped ensure that MDX has what it takes to venture off road and home again with confidence.

The results speak for themselves -- MDX will climb a 31-degree (60-percent) paved slope with a two-passenger load. It has 8 inches of ground clearance, a 28-degree approach angle, a 21-degree departure angle, and a 21-degree breakover angle for negotiating rough terrain. It can claw up a 28-degree (53-percent) dirt slope from a dead stop.

TOWING
The ability to haul pop-up campers, medium-sized boats, and recreational vehicle trailers is high on the priority list for many SUV owners. To understand this facet of the MDX's makeup, MDX engineers polled focus groups and studied survey results that tapped 200,000 households. Their findings offered the insights needed to properly outfit this new SUV to surpass the towing expectations of most customers.

Ultimately, the engineers concluded that a casual or weekend towing capability was most appropriate for MDX. Customer feedback helped set the towing limit at 4500 pounds for boats and 3500 pounds for other types of trailers. (A heavier load is acceptable with boats because their pointed bow shapes impose less aerodynamic drag on the towing vehicle than a slab-faced, square-cornered trailer.) The 3500/4500-pound rating is calculated to include up to four passengers and their cargo.

VARIABLE TORQUE MANAGEMENT' 4-WHEEL DRIVE SYSTEM (VTM-4')
The MDX is equipped with an advanced new type of 4-wheel drive system -- VTM-4. This system consists of a pair of wet clutches in the rear axle that are computer controlled to maintain traction in a variety of conditions.

Unlike other on-demand 4-wheel drive systems, MDX doesn't wait for slippage to go to work. Instead, torque is delivered to the rear wheels in proportion to forward acceleration to supplement front-wheel drive. This innovative proactive approach pays two dividends: On dry pavement, there's less likelihood of torque steer (a tendency for propulsion forces to tug at the steering and nudge the vehicle off line) plus more front tire adhesion available for cornering. In wet or snow conditions, automatic all-wheel drive gets the vehicle moving from rest with less chance of wheelspin.

If conditions are really slippery and wheel spin is unavoidable, VTM-4 instantly reacts by adding rear-wheel torque in proportion to both the slippage and the rate of increase of slippage. A special lock mode is also provided to help extract the vehicle from a stuck condition. To use this get-out-of-a-snowbank capability, the driver need only to move the lever to one or more of the two lower forward gears or reverse and then touch a button on the dash. With the lock mode engaged, VTM-4 automatically reduces the transfer of torque to the rear axle above six mph and reverts to front-drive by 18 mph.

DEFEAT WINTER OBJECTIVE
While studying competitive vehicles and the SUV marketplace, the MDX development team came to realize that a well-designed product could be an effective tool to defeat some of the frustrating rituals of the coldest months of the year. Based on that, members of the MDX development team that had grown up in northern parts of the U.S. drew on their personal backgrounds to formulate a clever "defeat winter" strategy for MDX -- consisting of a long list of designed-in features and systems aimed at providing superior cold-weather performance. The result is that MDX can be a major confidence builder for those faced with driving through severe winter road conditions.

The MDX's winter-beating tactics begin with a chassis engineered for excellent dynamics on wet, icy, or snowy pavement. The VTM-4 all-wheel-drive system has an electronic controller capable of reacting. The VTM-4 controller automatically engages four-wheel drive during acceleration to move the vehicle smoothly from a stop on slippery surfaces.

While some SUVs are prone to plowing wide when simultaneously accelerating from a side road and turning onto a main thoroughfare, MDX holds the desired line. The VTM-4 controller sends torque to the rear wheels any time that slippage is detected in front. Torque gradually increases in proportion to both the amount of front-tire slippage and the rate of increase of that slippage.

Of course, there are times when conditions are so bad that getting stuck seems to be unavoidable. To handle that circumstance, MDX is equipped with a VTM-4 Lock mode. The driver need only to move the shift lever into the two lowest forward gear positions or reverse and then push a button on the dash and to activate this feature. When engaged, the torque available at all four wheels is often enough to pull the vehicle back to sure footing.

Various other chassis details are also engineered with a priority on winter driving. MDX's Goodyear and Michelin tires are compounded with silica to enhance ice and snow traction at cold temperatures. Testing has demonstrated grip that is superior to many of the snow tires currently on the market. MDX's front suspension has a very low scrub radius so that braking on split-friction surfaces (such as a condition with one side of the vehicle on ice and the other side on dry pavement) does not tend to pull the vehicle to one direction or the other.

Total roll stiffness is equitably distributed so cornering response is linear and predictable even at low lateral Gs experienced during slippery conditions. The driveline is designed to provide natural and neutral handling response on snow and ice. Provided with a static ground clearance of 8 inches, MDX is unlikely to get mired in deep snow drifts. The Anti-Lock Braking System (ABS) is equipped with electronic brake-force distribution and four channels to provide maximum control even when traction varies dramatically from corner to corner. To preserve lateral stability, the rear brakes are programmed with a select-low strategy to modulate line pressure at both rear wheels as soon as either one approaches lock-up.

Features and amenities included as MDX standard equipment further enhance this SUV's winter-driving prowess. A rear heater is not only standard equipment but electronically linked to the operation of the front heater to speed warm up after a cold start. Heat is ducted to all seating positions. Rear seat heating is not available in the BMW X5, Lexus RX 300, or Mercedes-Benz ML 320.

And the list of features built into MDX that insulate driver and passengers from the effects of winter go on. MDX's window defogging performance is best in class. Electrically heated front seats are standard. Front mudguards are provided to deflect slush and stones away from the side of the vehicle. Extra seals positioned at the bottom of the doors keep mud and slush from building up on those lower surfaces likely to contact long coats, pant legs or dresses. Likewise the windshield molding and the outside rear-view mirror mounting trim are shaped to guide moisture flow away from the side windows for optimum foul-weather visibility. Door-mounted rear-view mirrors are electrically heated to clear frost and fog.

The windshield washer reservoir is a large 1.2 gallons for a generous supply of washer fluid, and an indicator light advises the driver when it's time to replenish that fluid. Washer nozzles are engineered for optimum performance with a fluidic design in front and a jet-type sprayer in back. Since keyless entry is standard equipment on MDX, owners will not be thwarted from entering their vehicle by a frozen lock cylinder.

Factory engineered accessories offered include the aforementioned rear mud flaps, an electrical engine-block heater, and a liner for the cargo compartment.

2001 Acura MDX - Powertrain

INTRODUCTION
An advanced powertrain is essential to meet MDX's primary goals of outstanding performance, class-leading low emissions, and excellent fuel economy. To that end the MDX is powered by an advanced 3.5-liter SOHC VTEC engine that delivers 240 horsepower at 5300 rpm and 245 lb-ft of torque from 3000 to 5000 rpm. Acura's renowned Variable Valve Timing and Lift Electronic Control (VTEC') valvetrain, first used in the NSX supercar, adjusts the timing, duration, and lift of the intake valves according to engine speed. In conjunction with a two-stage intake manifold, VTEC yields high peak-rpm performance, muscular response at low- and medium-rpm, very low emissions, and best-in-class fuel efficiency.

MDX's new 5-speed automatic transaxle has several features engineered specifically for use in a mid-sized luxury SUV, including: extra-wide gear ratios to optimize both start-up acceleration and highway cruising comfort, a lock-up torque converter and a rigid alloy case design.

The MDX's innovative VTM-4' (Variable Torque Management' 4-Wheel Drive) all-wheel drive system provides extra traction during acceleration and slippery road conditions. Additional benefits are improved dry-road vehicle dynamics, medium-duty off-road capability, and a lock feature to aid extraction from severe "stuck" conditions. A compact transfer case is bolted directly to MDX's front-mounted transaxle. A two-piece propeller shaft delivers torque from the transfer case to a rear axle drive unit. Two computer-controlled, electromagnetic-actuated clutches engage as needed to provide torque to the rear wheels.

POWERTRAIN SUMMARY
Engine

• 3.5-liter 60-degree V-6 with belt-driven single-overhead camshafts and four valves per cylinder
• 240 net horsepower at 5300 rpm; 245 lb-ft of torque from 3000 to 5000 rpm
• Remarkably broad and flat torque curve with 95-percent of peak output available from 2000 to 5500 rpm
• Variable Valve Timing and Lift Electronic Control (VTEC)
• Computer-controlled Programmed Fuel Injection (PGM-FI)
• Dual-stage induction system
• Direct Ignition System
• 100,000-mile tune-up intervals
• Meets ULEV emissions standards in all 50 U.S. states

5-speed Automatic Transmission

• Wide-ratio design provides a first gear with extra pulling power to start heavy loads in combination with a high top-gear for quiet highway cruising
• Components are engineered to provide the durability needed for both off-road and towing use
• Variable Torque Management
• Innovative, computer-controlled system unique to Acura MDX
• Uses integral single-speed transfer case, two-piece propeller shaft, and electromagnetically-actuated clutches in a rear axle drive unit to provide the best of all-wheel drive and part time 4-wheel drive
• Adds several attributes to normal front-wheel-drive handling and stability advantages
• Optimum vehicle dynamics during both dry and slippery conditions
• Extra traction and stability on snow and wet roads
• Rear-driving traction for off-road use
• Lock feature for getting unstuck from a snowbank
• 96 Kg system weight is significantly lower than competitor systems

Fuel Economy and Exhaust Emissions

• Preliminary EPA fuel economy ratings of 17 mpg in city driving and 23 mpg on the highway (best in class)
• First SUV certified as compliant with light-duty-truck Ultra Low Emissions Vehicle (ULEV) in all 50 states

ENGINE ARCHITECTURE
The Acura MDX's engine is an advanced 3.5-liter, SOHC, 24-valve, 60-degree, aluminum-block-and-head design that's significantly smaller, lighter, and more powerful than competitive SUV powerplants. A long list of technologies have been engineered to provide 240 horsepower, a broad and flat torque curve, very low emissions, high fuel efficiency, as well as exhilarating throttle response. The VTEC valvetrain and dual-stage intake manifold optimize cylinder filling efficiency across the engine's entire operating range. Low-restriction intake and exhaust systems, a 10.0:1 compression ratio, and roller-type rocker arms also aid efficiency.

ENGINE BLOCK
The MDX 3.5-liter engine's block is die-cast and heat-treated aluminum to minimize weight. A deep-skirt configuration is used to rigidly support the crankshaft, thereby minimizing noise and vibration. Thin-wall, centrifugally-cast iron liners help reduce overall length and weight. Each liner's rough as-cast exterior surface bonds securely to surrounding aluminum during the manufacturing process to increase strength and enhance heat transfer.

CRANKSHAFT/CONNECTING RODS/PISTONS
A forged-steel crankshaft is used for maximum strength, rigidity, and durability with minimum weight. Instead of bulkier, heavier nuts and bolts, connecting rod caps are secured in place with smaller, high-tensile-strength fasteners that screw directly into the connecting rod.

Short-skirt cast-aluminum flat-top pistons are notched for valve clearance.

CYLINDER HEAD
Unlike many SUVs, the Acura MDX has four-valve combustion chambers, the best approach to optimum performance with excellent fuel efficiency and very low emissions.

Valves are clustered near the center of the bore to minimize combustion chamber volume and to provide ample squish area. A 10.0:1 compression ratio helps maximize thermal efficiency, power output, and fuel mileage. One centrally located camshaft per bank is driven by a glass-fiber-reinforced toothed belt. Head gaskets are made of high-strength materials to contain combustion pressures.

VARIABLE VALVE TIMING AND LIFT ELECTRONIC CONTROL (VTEC)
Acura's innovative Variable Valve Timing and Lift Electronic Control (VTEC) is one key to maximizing engine output across the full operating range. Ordinary engines have fixed valvetrain parameters -- the same timing of events, valve lift, and overlap whether the tachometer needle is struggling to climb out of the low-rpm range or screaming at the redline. The VTEC approach instead has two distinct modes so that operation of the intake valves changes to optimize both volumetric efficiency (breathing) and combustion of the fuel-air mixture. Less air is needed in the lower portion of the engine's operating range so rocker arms are programmed to follow cam lobes that provide low lift and reduced duration (shorter time open with less valve lift). The two low-speed intake cam lobes for each cylinder are purposely different to provide asymmetric air/fuel mixture flow into the cylinder. This yields a swirl effect, a miniature whirlwind about a vertical axis that is highly beneficial to clean and complete combustion.

At 4100 rpm, the MDX's powertrain control module commands the VTEC system to switch intake valve operation to the high-speed mode. In response, an electric spool valve opens to route pressurized oil to small pistons within the intake-valve rocker arms. These pistons then slide to lock the three rocker arms provided for each cylinder together. As a result, both intake valves follow a central high-lift, longer-duration cam lobe. The switching process takes just 0.1 second and is undetectable by the driver.

The extra lift and longer duration provide the added air and fuel the engine needs to produce high peak horsepower and a broader torque band. Instead of a peaky engine -- one that isn't responsive through the mid-range then becomes raucous at high rpm -- the MDX has a powerplant that feels energetic and eager to provide exhilarating performance at any engine speed.

DUAL-STAGE INDUCTION SYSTEM
The induction system atop the MDX's V-6 engine works in concert with the VTEC valvetrain to significantly boost torque across the engine's full operating range. Internal passages and two butterfly valves commanded by the powertrain control module are configured to provide two distinct modes of operation. The valves are closed at lower rpms. In this mode, the three cylinders on each bank draw air from only the nearer half of the manifold's internal chamber, or plenum. The volume of the plenum and the length of inlet passages are both tuned to maximize the resonance effect, wherein pressure waves are amplified within each half of the intake manifold at certain rpm ranges. The amplified pressure waves significantly increase cylinder filling and the torque produced by the engine throughout the lower part of its rpm band. Funnel-shaped intake trumpets -- similar to those used on racing engines -- are fitted to the uppermost end of each intake runner to improve air flow.

As the benefits of the resonance effect dwindle with rising rpm, the butterfly valves open at 3,400 rpm to interconnect the two halves of the plenum, thereby doubling its volume. An electric motor commanded by the powertrain control module opens and closes the connecting butterfly valves via a cable. Now each cylinder draws intake air from the full plenum chamber. The inertia of the mass of air rushing down each intake passage helps draw in more charge than each cylinder would normally ingest. This phenomenon is the same effect produced by a low-pressure supercharger. The inertia effect greatly enhances cylinder filling efficiency and the torque produced by the engine at higher rpm. Concurrently, the VTEC system has switched from low-speed to high-speed valve timing to further enhance air flow through the intake valves and into each cylinder.

The net effect of the MDX's dual-stage intake manifold and VTEC valve train is that MDX delivers more torque and power than many of the large V-6s and small V-8s used by the competition, while also providing class-leading fuel efficiency and very low emissions. More than 95-percent of peak torque is available from 3000 to 5000 rpm. The corresponding band in the Mercedes-Benz ML320's 3.2-liter V-6 is only two-thirds as wide.

PROGRAMMED FUEL INJECTION (PGM-FI)
Fuel is delivered in sequence and timed to each cylinder's induction stroke by six injectors mounted on the lower portion of the intake manifold and aimed at each cylinder's central axis. A 16-bit, 32MHz central processor unit (CPU) within the MDX's powertrain control module calculates injection timing and duration after assessing an array of sensor signals: crankshaft and camshaft position, throttle position, coolant temperature, intake manifold pressure and temperature, atmospheric pressure, and exhaust-gas oxygen content. The CPU controlling the MDX's Programmed Fuel Injection, VTEC valve train, and dual-stage intake manifold also communicates with CPUs that regulate the five-speed automatic transmission and the Variable Torque Management all-wheel-drive system.

EXHAUST SYSTEM
A low-restriction, high-flow exhaust system is crucial to efficient power and torque production. Collector pipes upstream of the catalytic converter are a thin-gauge double-wall design using two concentric pipes separated by an insulating air gap. The catalytic converter is positioned only a short distance from the engine. This arrangement reduces the mass of exhaust system materials, thereby reducing the time needed to heat the catalyst after a cold start. The fast warm-up means that the catalyst begins cleansing the exhaust stream of emissions as soon possible. The catalyst, two muffling elements, and piping are all sized for high flow and low restriction. High-chromium stainless steel is used throughout the exhaust system for excellent durability. The twin exhaust outlets are polished for an attractive appearance.

DIRECT IGNITION SYSTEM AND KNOCK CONTROL
Maintaining the correct ignition timing throughout all operating conditions is essential to producing maximum power with minimal emissions and fuel consumption. The PCM examines various engine functions as well as a block-mounted acoustic knock sensor to determine optimum ignition timing. In the event the engine is supplied with fuel lower in octane than the specified unleaded premium, the PCM retards ignition timing as needed to forestall detonation. As a result, the engine constantly operates at the point of peak efficiency. Spark is supplied to platinum-tipped long-life spark plugs by six coil units positioned directly over the plugs in the cylinder-head access bores.

100,000 MILE TUNE-UP INTERVALS
The only maintenance necessary during the first 100,000 miles of driving is routine inspections and fluid and filter changes. At 105,000 miles, it's time to adjust the valves and to replace the platinum-tipped spark plugs.

DIRECT-ACTING CRUISE CONTROL
An electronic control unit automatically adjusts the throttle and requests transmission downshifts as needed to maintain a constant speed in the cruise-control mode. Three buttons used to engage and adjust the MDX's cruise control are conveniently mounted on the right side of the steering wheel. Speed can be varied in one-mph increments and the system can be disengaged without touching the pedals.

5-SPEED AUTOMATIC TRANSAXLE
An advanced 5-speed automatic transaxle was developed specifically for MDX to meet ambitious performance, driving enjoyment, and comfort goals. A lock-up torque converter is provided to maximize fuel efficiency. Torque-converter lock-up and shift timing are both managed by a 16-bit, 20-MHz transaxle CPU that maintains a communications link with the engine's CPU. Gear and clutch materials and the transaxle case itself are all engineered to support towing, off-road driving, and 4-wheel-drive use.

A notable feature of this unit's design is extra-wide gear ratios. The difference in torque multiplication between first and fifth gears is nearly 5:1 (4.932) to balance low-speed pulling capability against fuel economy and the ability to cruise quietly on the highway.

Creative use of a clutched idler gear permits the transaxle to provide five forward speeds with little more weight or bulk than a typical four-speed automatic. An over-running clutch is provided for first gear to smooth upshift quality. An extra-capacity transmission fluid cooler is offered with the MDX's optional tow package to maintain acceptable lubricant temperatures during heavy-load conditions.

A direct-control strategy is used to provide real-time pressure management of the transmission's clutches. Various safety and control strategies are in place to coordinate engine and transmission operation. For example, driveline shocks during up- or downshifts are minimized by momentarily reducing engine torque during the shift. In neutral and park, engine rpm is automatically limited to 5000 rpm.

For driving through hilly terrain, a Grade Logic Control system monitors throttle position and vehicle speed and acceleration to avoid hunting and excessive shifting. A lower gear is held for a longer-than-normal period to provide better climbing ability hills and more engine braking on downhill grades.

VARIABLE TORQUE MANAGEMENT (VTM-4') 4-WHEEL-DRIVE SYSTEM
After studying various all-wheel- and four-wheel-drive systems offered by the wide variety of SUVs on the market today, MDX engineers concluded that virtually every one had functional shortcomings and was undesirably bulky and heavy. The direct result of that research was the creation of an innovative system that automatically distributes torque to all four wheels as needed. Called Variable Torque Management 4-wheel-drive (VTM-4'), this new system provides front-wheel drive for dry-pavement cruising conditions and engages all-wheel drive only when there's a need to do so to improve mobility, stability, or maneuverability. Unlike many competitive systems that use an engagement strategy triggered by wheel slippage, the MDX's VTM-4 system anticipates the need for all-wheel drive and engages the rear wheels before slippage begins. Another special feature is a lock button, which temporarily holds engagement of the rear wheels to aid extraction from a slippery ditch or a snow bank. Patent applications have been made to safeguard innovative aspects of this new technology.

To avoid the weight and bulk of a conventional transfer case, VTM-4's torque transfer unit is a compact cast-aluminum housing bolted directly to MDX's transaxle. Since this vehicle is engineered for medium-duty off-road capability, the transfer case is a single-speed permanently-engaged device without the low-range offered by some SUVs. Attached to the front wheel differential's ring gear is a helical gear that provides input torque to the transfer unit. A short horizontal shaft and a hypoid gear set within the case turn the drive ninety degrees, move it to the vehicle center line, and lower its axis by approximately 3.75-inches.

PROPELLER SHAFT AND HALF-SHAFTS
The two-piece propeller shaft that carries drive torque from the transfer case to the rear-drive unit is made of high-strength steel tubing to permit a smaller diameter. Minimizing driveline dimensions improves both ground clearance and interior room. The cross yokes attached at each end by friction welding are forged steel for high strength and low weight. The center support bearing is rubber isolated to block the transmission of driveline noise from the interior of the vehicle. A low-friction plunger joint located near the center of the propeller shaft accommodates relative motion between front- and rear-mounted driveline components. A tuned-mass damper inside the front portion of the propeller shaft cancels any bending tendency in response to powertrain vibrations.

Equal-length front-wheel half-shafts have a plunger joint at their inboard end and a ball-type universal joint at the wheel end. Rear half-shafts are similar in design but use a double-offset joint at the inboard end and a ball joint at the outboard end. All universal joints are constant-velocity type.

REAR AXLE DRIVE UNIT
A conventional differential mechanism is not necessary in the MDX's rear final-drive unit. Instead, a hypoid ring-and-pinion gear set supported by a cast-aluminum housing switches torque from the propeller shaft's longitudinal orientation to the lateral orientation necessary to drive the rear wheels. Surface grinding the ring and pinion gear teeth yields the quiet operation expected of a luxury SUV wearing an Acura nameplate.

A connection from the ring gear to each wheel's half-shaft is made by left- and right-side clutches. Each drive clutch consists of three elements: an electromagnetic coil, a ball-cam device, and a set of 19 wet clutch plates which are similar in design to clutches used in any automatic transmission. Ten of the plates are splined (mechanically connected) to the ring gear while nine of the plates are splined to a half shaft. Left and right clutches are identical.

When the VTM-4 system's electronic control unit (ECU) determines that torque should be distributed to the rear wheels, an electric current is sent to the two electromagnetic coils. The resulting magnetic field moves a rotating steel plate toward each fixed coil. Friction between that steel plate and an adjoining cam plate causes the cam plate to begin turning. As it does, three balls per clutch roll up curved ramps, creating an axial thrust against a clutch-engagement plate. This thrust force compresses the wet clutch plates, thereby engaging drive to the corresponding rear wheel.

Unlike mechanically actuated four-wheel drive systems, the VTM-4 system is infinitely variable. The amount of torque provided to the rear wheels is directly proportional to the electric current sent from the ECU and can be adjusted from zero to a preset maximum. This current constantly changes to deliver the optimum rear torque calculated by the ECU. An internal gear pump circulates VTM-4 fluid to cool and lubricate the clutches, bearings, and gears within the rear drive unit. Use of high-strength, low-weight materials -- such as die-cast aluminum for the housing -- minimizes the bulk and weight of this hardware. In fact, the weight of the entire all-wheel-drive system is about 212-pounds, only two-thirds the weight of comparable equipped carried by the Mercedes-Benz ML320.

There are three distinct modes of VTM-4 engagement. The first -- called the acceleration torque control (ATC) mode -- is unique to this system. It works even on dry pavement to distribute driving torque to all four wheels as the MDX accelerates from a stop to cruising speed. One notable benefit is that traction is immediately available to move the vehicle from rest through a slippery intersection before slippage occurs. (Once a wheel slips, the traction available for forward propulsion and lateral restraint is significantly diminished.) A second advantage is that apportioning drive torque among all four wheels greatly diminishes the likelihood of torque steer. Handling dynamics are also improved. Reducing the propulsive force carried by the front tires leaves more adhesion for steering the vehicle into a tight bend or for holding cornering arc in the middle of a turn. In other words, the MDX's dynamic balance is greatly enhanced by ATC logic.

Rear wheel torque rises smoothly from zero to the maximum setting in proportion to vehicle acceleration (both forward and reverse). At higher speeds, the front wheels are capable of providing the desired thrust with excellent handling so torque delivered to the rear wheels automatically diminishes with speed. During constant-speed driving, all driving torque is delivered by the front wheels in the interests of smoothness, quietness, and fuel efficiency.

The second engagement mode uses wheel slippage control logic. If the difference in rotational speed between front and rear wheels rises because of a slippery surface or poor traction at the front of the vehicle, that condition is detected by wheel-speed sensors which are monitored by VTM-4's ECU. In response, the ECU commands an increasing amount of torque for the rear wheels. Torque is proportional to both slip rate and the rate at which the slip rate is increasing. This operation is similar to conventional slip-based all-wheel-drive systems already on the market.

The third mode of all-wheel-drive engagement is activated when the driver taps a lock button mounted on the instrument panel. The maximum amount of rear-drive torque is locked in until the vehicle gets moving and exceeds six mph, at which time rear drive torque is gradually diminished. By 18 mph, the lock mode is fully disengaged. The shift lever must be in the first, second, or reverse-gear position to use the lock mode.

The maximum torque delivered to the rear wheels is sufficient to climb the steepest grade observed on any public road in America -- 31 degrees (60-percent slope) -- with a two-passenger load on board. The MDX will also move from rest up a 28-degree (53-percent slope) dirt grade. On a split-mud grade (different amounts of traction at each wheel), VTM-4 automatically provides sufficient rear-wheel torque to help the vehicle climb a steep, slippery driveway to enter a garage.

2001 Acura MDX - Chassis

INTRODUCTION
The Acura MDX is the first product in an uncharted portion of the market: a car-like, family-sized, luxury SUV. To venture beyond current competitive offerings with a no-compromise design, a new chassis was essential. Engineered to deliver the exhilarating driving experience and the outstanding vehicle dynamics expected of Acura products, MDX exceeds conventional SUV chassis design standards by a wide margin.

Key design elements selected to meet ambitious driving dynamics goals are as follows:

• Extra-wide track dimensions
• Short wheelbase for agility
• Rubber-isolated front and rear subframes
• Independent front and rear suspension systems with car-like geometry and a long wheel travel for sporty handling and a comfortable ride
• 17-inch cast-aluminum wheels and tires
• Radial tires with silica tread compound for excellent traction and fuel economy
• Four-wheel disc brakes with four-channel ABS and electronic distribution
• Engine-speed-sensitive rack-and-pinion power steering

FRONT SUSPENSION
A wide track -- 66.3-inches front, 66.5-inches rear -- was specified for MDX to optimize handling, stability, and ride comfort parameters. The strut-type front suspension provides a generous 7.3 inches of wheel travel (4.3-inches in compression, 3.0-inches in rebound) with a moderate spring rate and relatively firm damping. Separate load paths to the unit body are provided for the coil spring and the shock absorber to facilitate tuning out road noise. A solid 0.9-inch anti-roll bar is linked directly to the strut via ball-joint connections to resist body roll during cornering maneuvers. The small 0.04-inch scrub radius designed into the front suspension is unusual for SUVs but this feature gives the MDX car-like steering response and handling that's consistent and predictable in on- and off-road situations. Accelerating or hard braking with uneven traction underfoot does not cause MDX to drift off line as is the case with many SUVs.

A low roll center (6.2-inches above the ground) further adds to MDX's handling characteristics. The lower control arm bushings are designed to provide a stabilizing toe-out steering effect when loaded during braking or cornering. The L-shaped arm allows a very tight steering lock for good low-speed maneuverability. In fact, the Acura MDX's turn-circle diameter is a modest 37.2 feet, some four feet tighter than the Lexus RX 300's turning circle.

FRONT SUBFRAME AND MOUNTING SYSTEMS
The MDX's engine, transaxle, transfer case, steering gear, and front suspension are all supported by a welded-steel subframe secured to the unit body's longitudinal rails through four tuned rubber isolation mounts. The front of the subframe assembly is tubular for maximum stiffness with minimal weight. A stiffener located under each subframe attachment fastener helps stabilize the assembly, thereby sharpening handling and braking performance. A stiffener plate bolted across the subframe under the transfer case greatly increases the assembly's rigidity. Two dynamic and one mass damper are positioned to counteract noise and vibration, while two fluid-filled engine mounts quell vibration at idle and isolate powertrain NVH from the passenger compartment. The steering gear mounts are made of heat-resistant rubber to provide good vibration isolation, the firm retention necessary for sensitive on-center-steering feel, and life-of-the-vehicle durability.

POWER RACK-AND-PINION STEERING
MDX's steering system is tuned for quick, linear, car-like response and sensitive feel -- and the engine-speed sensitive power steering assist is high for parking maneuvers and low at highway speeds. One key to maneuverability and agility is MDX's relatively short 106.3-inch wheelbase.

REAR SUSPENSION
The MDX's rear suspension is a compact multi-link trailing arm layout for excellent ride and handling characteristics, minimum weight, and optimum packaging. Wheel travel is a generous 4.9 inches in compression and 3.3-inches in rebound. The three links that position each rear wheel laterally run between the knuckle assembly and the subframe. A trailing arm also runs from the unit body to each rear knuckle. Coil springs seat on the lowermost lateral link and anchor against the unit body directly behind each axle shaft. Shock absorbers, positioned ahead of the drive shafts, run from a low point on each knuckle to a secure attachment point on the unit body. Knuckles are an "in-wheel" design to optimize suspension geometry and packaging efficiency. Bushing compliance provides a modest toe-in effect in response to substantial cornering and braking loads to enhance dynamic stability. A solid 0.8-inch anti-roll bar helps keep the body relatively flat during hard cornering. The rear roll center is positioned at a 6.7-inch height to provide linear and predictable behavior at the limit of adhesion. The results speak for themselves, as MDX truly sets a new standard for ride and handling in the luxury SUV category.

REAR SUBFRAME
Packaging of major components at the rear of the MDX is a major engineering challenge. The rear subframe, which supports most of the rear suspension and the rear axle drive unit, is made of high-strength steel for high stiffness and minimal weight. The shape of the rear subframe is equally important -- it must accommodate the drivetrain components for the VTM-4 four-wheel drive system, the multi-link rear suspension pieces and still allow the versatility of the third-row seat and flat cargo flow. For excellent ride and handling characteristics, the subframe attaches to the unit body at four widely spaced, rubber-isolated mounting points. Rear-suspension components, especially the springs and shock absorbers, are as compact as possible to facilitate a wide, flat load floor and to leave room for both a spare tire and a full-size fuel tank. The rear axle drive unit is mounted to the subframe by means of rubber isolators to block road and powertrain noise and vibration from the passenger compartment. A tuned dynamic damper attached to the drive unit cancels propeller-shaft and drive-shaft vibration.

WHEELS AND TIRES
Two different die-cast aluminum wheels are offered for the MDX. Both have 6.5-inch-wide by 17-inch diameter rims, a 45mm offset dimension, and five-lug bolt pattern. Large openings in the wheels provide ample brake-system ventilation. Tires supplied by Michelin and Goodyear are both sized P235/65R-17 and carry an M+S (mud and snow) label and a T (118 mph) speed rating. Both the tread and the carcass were designed with computer-aided tools to achieve excellent riding comfort, low noise and wear, and best-in-class all-weather performance. Tread materials are compounded for excellent winter traction and include silica for low rolling resistance. During cold weather engineering tests, the MDX's tires consistently outperformed some of the most highly rated snow tires on the market.

The compact spare tire is carried under the rear load floor and can be lowered by turning a hex-head bolt hidden with the provided lug-nut wrench. The hex-head bolt is located under a cover conveniently located in the rear hatch trim area. This arrangement guarantees the security of the spare and keeps it readily accessible without disturbing luggage or cargo carried onboard. Room is provided to stow a flat or a full-size spare in the compact spare's location. Corrosion and failure of spare tire retention equipment, a common problem in some competitor SUVs, is avoided by use of stainless steel and polymer materials eliminating high-mileage failure.

BRAKING SYSTEM
MDX is equipped with state-of-the-art four-wheel disc brakes and a Bosch 5.3 four-channel anti-lock braking system. For optimum performance with widely varying loads -- including the possibility of towing -- braking distribution is managed electronically. At the rear, a select-low braking strategy is used to preserve directional stability in slippery driving. In the event one rear wheel verges on lock-up, triggering a pressure modulation at that wheel, brake pressure is also diminished at the adjoining wheel to preserve the rear axle's lateral stability.

Extra-large brake rotors and calipers provide the capacity necessary for short stopping distances and excellent fade resistance -- even with a heavy load in tow -- and the precise pedal feel expected of an Acura. The vented front rotors are 11.8-inches in diameter and 1.1-inches thick. Solid drum-in-disc rear rotors are 12.3-inches in diameter and 0.43-inch thick. A drum-type parking brake mechanism is positioned within the inner portion of the rear rotor. Parking brakes are both set and released by stepping on a pedal, freeing space in the console area. The tandem-type vacuum booster consists of two 9-inch diameter booster chambers.

Braking hardware is tuned for quick response, low effort, and short pedal travel. The combined system -- brakes, ABS, tires, chassis -- yields stopping performance notably shorter than MDX's key competitors. The MDX is capable of carrying heavy loads or towing a 4500-pound boat or a 3500-pound trailer when equipped with the towing package.

ANTI-LOCK BRAKING SYSTEM (ABS)
MDX brake components are large in capacity to help handle heavy loads -- both those carried on board and those towed behind. Front-to-rear brake effort proportioning is electronically regulated. The Anti-Lock Braking System (ABS) system has four sensing and activating channels to detect a wheel on the verge of lock up. In the event this occurs, brake pressure is held, then reduced, to permit that wheel to regain traction before full braking resumes. A select-low strategy controls the braking effort at both rear wheels as soon as one nears lock up to safeguard lateral adhesion and to help avoid any tendency to spin or fishtail during hard braking.

MDX's ABS is especially effective at maintaining a straight heading on split-friction surfaces where one track encounters snow or ice while the other rolls on dry pavement. The front suspension geometry has a very small scrub radius to help keep the MDX running true even when one front wheel is braking harder than the other because of uneven traction conditions.

TIRES
Low-profile Goodyear and Michelin radial tires provide outstanding adhesion. During dry pavement handling tests, MDX demonstrates significantly higher cornering grip than other luxury SUVs. As cornering forces rise, understeer is mild and linearly progressive to accentuate predictability. The power-assisted rack-and-pinion steering is tuned for on-center sensitivity and slack-free response. Consistent with the desire to provide a rewarding driving experience, MDX's overall steering performance is best-in-class.

FUEL SYSTEM
The 19.2-gallon, saddle-shaped fuel tank is molded of high-density polyethylene (HDPE) for low weight, freedom from corrosion, and impact resistance. It's positioned immediately ahead of the rear wheels and over the propeller shaft to guard against collision damage. Corners of the tank are rounded and the inside of the tank is baffled to diminish the likelihood of sloshing-fuel noise. The HDPE filler pipe and fuel lines are light, not susceptible to corrosion, and resistant to fuel vapor losses. A high-efficiency fuel pump is housed inside the fuel tank. The fuel-filter is a lifetime design that never needs replacement.

MDX complies with all evaporative emissions, on-board diagnostics, and refueling vapor recovery requirements. The fuel vapor canister and filter are rubber mounted for noise isolation and protected against rock and debris damage by a deflection shield.

TOWING
The ability to haul pop-up campers, medium-sized boats, and recreational vehicle trailers is high on the priority list for many SUV owners. To understand this facet of the MDX's makeup, MDX engineers polled focus groups and studied survey results that tapped 200,000 households. Their findings offered the insights needed to properly outfit this new SUV to surpass the towing expectations of most customers. Engineers learned that roughly a third of the six-cylinder-powered-SUV owners expect to tow something at one time or another. Eighteen-percent tow more than four times per year. And approximately ten percent of the miles accumulated on six-cylinder SUVs are with a trailer in tow.

Another notable discovery was that many customers aren't particularly knowledgeable about towing technicalities. Terms like "gross axle weight" may be germane to the engineering process but such language can leave average customers in a state of bewilderment. This realization convinced engineers that customers' interests are best served by load ratings that are both realistic and easy to comprehend.

Ultimately, the engineers concluded that a casual or weekend towing capability was most appropriate for MDX. Customer feedback helped set the towing limit at 4500 pounds for boats and 3500 pounds for other types of trailers. (A heavier load is acceptable with boats because their pointed bow shapes impose less aerodynamic drag on the towing vehicle than a slab-faced, square-cornered trailer.)

Industry practice is to boast a high maximum tow rating, even though some sacrifice of passengers and cargo may be necessary to suitably accommodate such a trailer load -- in some cases limiting the vehicle to one passenger to accommodate the maximum specified towing capacity. The Acura MDX's 3500/4500-pound rating is calculated to include up to four passengers and their cargo.

To help ensure that customers will be able to move a maximum rated load up a grade from rest (such as pulling a loaded boat trailer up a launch ramp), engineers sought out the most challenging entry roads and launch ramps in the country. Through testing, they verified that MDX proficiently handles the 17-degree (31-percent) grades on mountain roads approaching Lake Cumberland in southern Kentucky and the strenuous combination of 15-degree (27-percent) grades and 5280-foot elevation at Lake Tahoe. A note in MDX's owner's manual suggests reducing gross combined weight two-percent for every 1000 feet of elevation. At sea level, MDX can move a 4500-pound boat and four passengers up an 18-degree (32-percent) slope.

In support of safe towing, MDX's tow hitch and other hardware needed for the job is factory engineered for dealer installation. A standard automatic transmission cooler built into the radiator is adequate for towing up to 2000 pounds. For heavier loads, the addition of a second external transmission cooler and a separate power-steering fluid cooler is required. The dealer-installed trailer hitch is a Class III receiver-type design that bolts on with no drilling, cutting, or bumper-cover modifications. A harness to provide electrical power to trailer lights plugs into a connector provided at the rear of the vehicle.

2001 Acura MDX - Body

INTRODUCTION
To pursue a new direction in the luxury SUV segment, Acura envisioned MDX as the first SUV with truly car-like ride and handling characteristics with the benefit of a family-sized SUV interior. By avoiding some of the compromises that other manufacturers have accepted, MDX combines a dynamic performance experience, utility and luxurious accommodations with the value expected of all Acura vehicles. The MDX concept rests on these four fundamental principles:

• Interior and exterior designs that are consistent with Acura philosophies of intelligent design, elegant styling, thoughtful features, packaging efficiency and high value
• Exterior styling that subtly expresses the vehicles athleticism without indicating the surprising flexibility and functionality of the interior
• The versatility to quickly and easily adapt the interior space to a variety of useful and practical layouts that reflect the varied and often contradictory needs of SUV buyers
• Well-balanced vehicle dynamics to reward the driver with a feeling of exhilaration during sporty driving, the capability for medium-duty off-road driving and the competence needed to conquer winter conditions and the power required for towing

EXTERIOR DESIGN
The Acura MDX design concept was born at Honda's R&D facilities in Torrance, California. Designers selected the freedom of the Southwest as a conceptual theme for the exterior design. Acura's new SUV celebrates the enjoyment of vast open spaces, the beauty of dramatic landscapes, aggressive mountain and desert terrain, versus the modern urban environment. MDX is purposely different from conventional SUVs -- a theme that carried through from the very initial stages of development.

The MDX adopted a clean, strong and elegant exterior appearance to allow a functional and versatile interior space. The lines were penned to create a natural flow from front to rear, as if MDX was sculpted from one solid piece to reinforce the sense of strength and ruggedness. The individual surfaces of the hood, fenders and doors are more finely sculpted with detailed character lines that are both attractive and functional -- simultaneously strengthening the panels and managing airflow over MDX's aerodynamically efficient shape. The solid front is anchored by the familiar pentagonal Acura grille, around to the more intricately detailed greenhouse area that culminates in a D-pillar that sweeps gently forward. This D-pillar design is important to the overall shape of MDX -- it finishes the look of this finely sculpted shape while providing a functional design for MDX's rear liftgate. Form and function work hand-in-hand as the forward upper edge of the liftgate allows the rear hatch to open with minimum clearance required behind the vehicle. This simplicity and elegance of design is a metaphor for MDX as a whole -- each design element has been carefully thought out to result in a vehicle that is as pleasing to the eye as it is to drive and use.

Focusing on environmentally conscious attributes, MDX designers shaped the vehicle's exterior to minimize aerodynamic drag and specified use of recycled materials where possible. Their goal was to make this product a significant leap forward in environmental awareness and, ultimately, the intelligent SUV choice for sophisticated buyer. The aerodynamically efficient shape contributes to MDX's low wind noise and improves highway fuel economy.

Designers first selected a personality for the MDX: rugged -- yet sophisticated and refined, practical -- yet enjoyable, styling that is honest and lacks superficial clichZs and unnecessary trim. Then the designers mapped out a fresh set of proportions to meet the development goals. They incorporated a full-size interior into a mid-size-SUV's exterior space. That meant stretching exterior width to maximize the available interior space and to benefit dynamic stability. They made the cabin as long as possible in the interests of interior roominess. They selected a short hood and a strong frontal appearance and they shaped the vehicle's corners to refine MDX's aerodynamic performance. To enhance off-road capability, they specified a high ground clearance but also provided a low door opening to ease entry and egress. In the side view, the body-to-glass proportion was optimized for a sporty demeanor. Windows were maximized for excellent outward visibility.BODY STRUCTURE
MDX's body structure is an all new design to meet the rigorous requirements of this challenging assignment -- including best-in-class collision performance targets. Several advanced unit body concepts have been applied to yield a structure with outstanding levels of occupant protection. High rigidity is another top priority. A stiff structure is essential for achieving balanced and predictable handling and to assure that the ride is smooth and quiet for the life of the vehicle. At the same time, reducing weight is a key to the well-rounded performance demanded of MDX -- dictating the use of high-tensile steel in many critical areas. To achieve their high goals for safety and performance, MDX engineers used powerful computer simulation and analysis tools to optimize body design and conduct virtual collisions before the first prototypes were even constructed.

To meet the MDX's ambitious strength, stiffness, and weight targets, body engineers selected a unit body design with rubber-isolated front and rear subframes. The high level of bending and torsional rigidity designed into the MDX body structure helps improve handling by providing a rigid platform for mounting the suspension components.

Like all Acura products, MDX's body is designed to deform progressively in front, side and rear collisions. Engineering front, side and rear sections that absorb the energy of a collision reduces the likelihood of occupant injury. A highly rigid passenger section is reinforced laterally and longitudinally to maintain its size and shape for omnidirectional protection.

Most of the MDX's rigidity and resiliency comes from its robust floor construction. Two longitudinal rails run the length of the vehicle, from bumper to bumper. These rails are buttressed by a total of eight box-section crossmembers at critical points along the vehicles platform and further reinforced by two bumper bulkheads. This provides the strength needed to resist standard barrier impacts at the front and rear, offset crashes (wherein most of the load is applied longitudinally to one corner of the vehicle), and side impacts.

A passenger compartment safety shell design is used to protect occupants with structural 'rings' at the A, B, C, and D pillars that run continuously around the circumference of the vehicle to help minimize intrusion during side impacts. Reinforced steel stiffeners inside the doors at the beltline provide a continuous horizontal connection between the first three pillars. High tensile-strength steel tubular beams inside the door structure at wheel height provide additional intrusion resistance. A single-piece side-ring design is used to assure tight and consistent fit and finish in the critical closure (doors, windows) areas, and the doors are made using laser-welded tailored blanks. This innovative door design uses higher-gauge steel in high-stress areas and lighter weight steel in other areas to save weight yet maintain structural integrity for durability and safety. About one quarter of MDX's steel body parts are high-tensile steel. Longitudinal rails, floor crossmembers, and pillar reinforcements that carry heavy loads are made of the stronger heavier gauge steel. A roof-mounted reinforcement is provided to secure the center-rear passenger's upper-torso restraint.

One of the toughest challenges facing an SUV body-structure engineer is achieving adequate stiffness in the rear hatch opening. If the design is inadequate, the result is squeaks, rattles, cracks in the body, and premature rust (caused by metal fatigue). Static load tests of the MDX body structure showed that it's 30-percent stiffer than the Lexus RX 300 in this particular area.

The use of high-strength, closed-section steel bumper beams helped move MDX to the head of its class in this area. The cumulative damage from a battery of four crash tests costs significantly less to repair than the same damage inflicted on primary competitors.

Powerful simulation and analysis tools were used more extensively than in any past Acura product development to verify that the MDX was capable of meeting performance targets before physical development tests were conducted for verification purposes. These tools facilitate rapid evaluation of changes in component shape, location, strength, and attachment to predict areas that need further development to optimize the design. That, in turn, minimizes the time and cost needed to construct and test multiple prototypes.

The bottom line is best-in-class collision performance, according to internal test results. MDX is expected to earn five stars in federal government New Car Assessment Program (NCAP) frontal barrier tests and Side Impact (SINCAP) tests. A 'good' rating is expected from the Insurance Institute for Highway Safety's offset barrier tests.

AERODYNAMIC DESIGN
A low aerodynamic drag coefficient was essential to achieve MDX's goal of best-in-class highway fuel efficiency. Toward that end, MDX has been styled with a sloped and tapered front-end design. The windshield is tilted to a low angle to help air flow smoothly over the roof. At the trailing edge of the roof, a tapered surface minimizes wake turbulence. A chin spoiler integrated below the front bumper deflects air to the sides that would otherwise flow under the vehicle. A strake (air deflector) is also positioned ahead of each front tire to direct air to the smooth sides of the vehicle. The net result is a drag coefficient that's a class-leading 0.36 Cd. As a result, EPA highway fuel efficiency is a class-leading 23 mpg, the best of any mid-size luxury SUV.

LAMP DESIGN
Front-of-vehicle illumination is integrated into one attractive and aggressively styled halogen lamp assembly. Following the lines of the deep V-channel shape of the grille, the lamp assemblies wrap around to the forward edge of the front fenders, providing a natural transition from the vehicles front to its side. A clear outer lens is used to provide a clean look and allow smooth air flow around the vehicle's front corners. The innermost lamp is for high-beam illumination; it uses a round reflector. In the middle position, a multi-faceted, rectangular-shaped low beam is sited for excellent near-vehicle illumination. Turn signals, marker lamps, and reflectors occupy the outboard position.

Fog lamps are standard MDX equipment. For a consistent appearance, a clear lens and a multi-faceted reflector are used for this lamp. The foglamps are positioned just below the bumper surface adjacent to the lower air intake.

Four lights and a reflector are integrated into one lamp assembly positioned at each rear corner of the MDX. At the top is a combination stop and tail-lamp. Directional signals and back-up lamps reside in the middle position. A tail/stop lamp is located in the bottom half of the assembly. At the lower edge is a reflex reflector. A circular back-up-lamp reflector provides extra illumination at the rear for while backing up.

GLASS
Excellent visibility was a high priority to provide MDX drivers with a commanding view of the road ahead and to give passengers a pleasant open feeling, calling for narrow yet strong roof pillars. MDX provides an outstanding 286 degrees of outward visibility, a six-percent advantage over some mid-size SUV competitors.

To control the migration of water over the front door glass, windshield side moldings were extended to create a dam that helps channel rain and sleet up and over the roof. Another subtle touch is the rear edge of the outside rear view mirror's mounting base; squaring that surface benefited air flow patterns and reduced wind noise.

DOOR DESIGN
Many SUVs have plastic cladding on their lower body surfaces. A damage analysis study by MDX engineers revealed that cladding positioned low on the side of the vehicle actually offers little protection from parking lot and garage scarring because contact is far more likely to occur at the mid-point of the door or higher. For this reason, and in the interests of providing customers with a clean, strong, and elegant appearance, MDX is not equipped with side-surface cladding.

Another discovery was that dirt and mud can build up on vertical sill surfaces below the door seals. This is an annoyance because the dirt often soils pants, dresses or other clothes as occupants enter the vehicle. To avoid this problem, an extra seal has been included at the lower interior edge of each door. These seals rest against the side sill garnish and block the build up of dirt and debris, ensuring clean and hassle-free entry and egress -- no matter what outside conditions might provide.

Special measures have been taken to make MDX highly resistant to intrusion by thieves and vandals. The liftgate is not equipped with an exterior lock cylinder and can only be unlocked with either a remote keyfob or the interior switch -- either method requiring that the operator has key access to the vehicle. Reinforced steel guards have been installed to deflect break-in tools away from the front door lock rod and latch mechanism. A double thickness of steel around the driver's door key cylinder stops vandals from prying their way into the vehicle -- and for added security only the driver's door is equipped with a traditional key-lock cylinder.

The window sashes are equipped with continuous window frame guides that completely surround the door glass and limit access through this sometimes vulnerable area of the vehicle. And rear lock rods are positioned behind the center sashes so they are inaccessible from outside the vehicle.

REAR-VIEW MIRRORS
The use of blue-tinted door mirror glass greatly reduces sun and headlamp glare to the driver. For the convenience of owners of the MDX with the Touring Package, each of the two keyless remote key fob units are pre-programmed so the mirror (and driver's seat) settings automatically match the memory settings of that particular driver.

The MDX Touring Package adds another handy feature -- when the transmission is shifted into reverse, the right-side mirror angles down 15 degrees for better visibility near the vehicle. This feature can be disabled by moving the power mirror adjuster switch out of the center position.

MDX engineers provided electrical heating to the outside mirrors not only to defog them in winter but also to reduce the likelihood their surfaces will be damaged by contact with ice scrapers.

WASHER AND WIPER SYSTEMS
As part of the MDX's "defeat winter" goal, engineers invested extra effort in a rear-window washer and wiper systems that works exceptionally well. The wiper arm is a clean one-piece design with a European appearance. Nearly two-thirds of the glass area is swept compared to only 53 percent in a popular domestic SUV. A jet-type washer nozzle is positioned to help distribute the fluid for quicker and more thorough rear-window cleaning. Fluid is delivered almost the instant the wash button is touched thanks to use of a check valve in the delivery line.

Two single-piece wiper arms are also used in front. Fluidic nozzles are fitted here for several reasons. They have a large orifice that covers more surface area and they're less likely to clog than a conventional nozzle. They clean the windshield with fewer wash cycles.

ROOF RACK
Designed to accentuate both the styling and utility of MDX with Touring Package, the integrated design of the roof rack (standard on Touring model, available as an option on standard model MDX's) consists of two fixed bars that mount in the rain channel of the roof. The cross bars are designed to carry items weighing up to 150 pounds depending on how the weight is distributed. Engineers optimized the location of the bars for loading convenience and the roof rack cross-bars have an airfoil-shaped cross-section to avoid wind noise. They're made of plastic-sheathed steel for high stiffness and durability. The rugged-design adjustable end stays are sturdy zinc die-castings covered with stylish trim. The rack is a standard feature on the MDX with Touring Package and offered as a dealer-installed accessory on the MDX. Accessory components are offered to facilitate transporting skis and bicycles or a variety of other items.

RADIO ANTENNA
For optimum radio reception, the MDX's antenna is a short, flexible, damage-resistant design positioned at a rear-center location on the roof. This antenna provides good reception, with the security and enhanced appearance roof-mounting as opposed to more common fender- or A-pillar type mountings.

SPARE WHEEL AND TIRE
The compact spare tire is carried under the rear load floor and can be lowered by turning a hex-head bolt with the provided lug-wrench. The mounting bolt is neatly concealed under a cover conveniently located inside the rear hatch trim area. This arrangement guarantees the security of the spare and keeps it readily accessible without disturbing luggage or cargo carried onboard. Room is provided to stow a flat or a full-size spare in the compact spare's location. All spare tire mountings and hardware are made of stainless steel and polymer materials to minimize corrosion that can occur over time.

MOON ROOF WIND DEFLECTOR
Wind noise can be annoying when the sunroof is open in any large-interior-volume vehicle. MDX engineers solved this problem by providing a simple wind deflector that automatically rises into the air stream when the glass moon roof is opened. An aluminum blade and composite end pieces are used to save weight. As a result of this effort, the MDX is one of the quietest SUVs on the market with the moonroof in either the open or closed position.

2001 Acura MDX - Interior

INTERIOR DESIGN
In the MDX, clean solid forms on the instrument panel and door areas define a wide open and luxurious space. Positioned within that space are the driver's cockpit and a multi-use console that are reminiscent of Acura's other models. Grained panels and leather trim throughout the interior complement the design.

The focal point of the instrument panel is the personal computer aspect of the center control panel for HVAC, music system, trip computer and the available navigation system. The console storage compartment offers a wealth of functional features without diminishing the overall sense of roominess. Control switches, beverage holders, storage pockets, power outlets, and audio speakers are located throughout the interior to offer a remarkable degree of ergonomic functionality while upholding the desired clean, purposeful theme. Seats are designed with a luxurious, stylish appearance and a sporty image consistent with this product's exhilarating driving attributes.

Front and side airbags for the driver and front seat passenger are standard, along with a headrest and 3-point safety belts are provided for all seven passenger seating positions. In the interests of versatility, second- and third-row seats were designed for easy configuration from seven-passenger vehicle to cargo vehicle with a flat cargo floor -- or any of many layouts somewhere in between the two extremes. And to make the most use of the interior volume, an under-floor storage compartment is also provided behind the third row of seats.

The new Acura MDX has an interior with more useable seating and cargo space than any of its key luxury SUV competitors -- without resulting in a bulky exterior. This was achieved by taking advantage of its extra-wide wheel-track dimensions and an innovative driveline that delivers exemplary power, performance, and all-wheel-drive traction without intruding on interior space. MDX's interior has a low, flat floor for the first- and second-row seating positions for easy entry and egress. The lack of a large and intrusive driveshaft tunnel and unwieldy rear-axle intrusion yields room for up to seven passengers in three seating rows, a highly versatile center console and a cargo area wide enough to accept four-foot-wide sheets of building materials.

In keeping with Acura's tradition of selling fully featured products, MDX offers a wealth of power-operated accessories, conveniences, and refinements as standard. Notable innovations include the world's first SUV with a synchronized front and rear climate control system engineered for rapid warm-up in cold weather, expedient cool-down during summer months, and good all-around comfort for all seven passengers. The center console is designed to provide a front-seat armrest, a handy storage compartment, and second-row-passenger's serving tray. A large central LCD display screen houses the standard multi-function trip computer and the available DVD-based satellite-linked Acura Navigation System. In both cases, climate-control buttons and displays are also integrated within the display screen for easy access and viewing and operation. Both the standard and enhanced Bose sound systems play AM/FM, CD, and cassette source material. The premium Bose system adds in-dash six-CD changer capability and an additional 8-inch speaker.

MDX's steering wheel uses a thick rim section for a sporty, substantial feel. The leather cover is perforated in grip areas to prevent slippage, and cruise control switches are positioned between the right-side spokes while switches to manage the music system volume and station or track are in a corresponding position on the left.

The transmission shift lever is covered in a matching perforated leather material. It moves through a gate that helps the driver quickly find the desired gear position. Perforations in the center panels of the leather seating surfaces extend the theme established in the shift lever and steering wheel to seating surfaces.

SEVEN-PASSENGER SEATING ACCOMMODATION
Three-row seating -- two bucket seats in front, a three-passenger 60-40-split middle-row bench seat, and a two-passenger 50-50-split bench seat in back -- is standard Acura MDX equipment. Leather-trimmed seating surfaces for the front two rows is also standard. Third-row seats are upholstered in a leather-like matching vinyl material for resistance to spills, dirt and other hard use.

The driver's seat features eight-way power adjustment and a special lumbar support that flexes to match the natural curve of the spine under the weight of a passenger. Both the upper torso and the pelvis are held in an orthopedically correct position. The lower cushion design provides excellent comfort, even for larger occupants. Side bolsters are configured to comfortably hold the driver during spirited driving without impeding ingress and egress. The relatively flat, open design of both front seats give the driver and front passenger the freedom to adjust seating positions easily for added comfort on long trips. Integrated headrests and electric heating elements are standard with the Touring Package in both front seats. The memory seating positions -- as well as the rear-view mirror pre-sets -- are matched to either one of the two keyless remote entry fobs, and automatically adjust to each driver's pre-selected positions.

All seating positions have three-point seat belts. Front seat belts are equipped with pretensioners and automatic load limiters that are activated in certain collision conditions. The MDX comes with standard driver's and passenger's front airbags. The dual-stage passenger's front airbag can deploy at the most appropriate of two rates -- depending on the severity of the crash. In addition, if the driver's or passenger's seat belt is not fastened, the airbag deploys at a lower collision speed to help offer more protection to the unbelted occupant.

The driver's and passenger's seats also feature side airbags mounted in the seat bolster closest to the door. The front passenger's seat is equipped with a system designed to disable side airbag deployment and prevent injury to a small child (or small-statured adult) if they lean into the side airbag deployment path. Once the child returns to an upright seating position, the side airbag will reactivate so it can deploy and protect the child in a side impact.

MDX's middle-row seat is a 60-40-split design with comfortable room for three passengers, height-adjustable headrests, and a fold-down combination armrest and dual cupholder. To comfortably accommodate taller passengers, MDX engineers located seat height a reasonable distance above the flat floor and made the door openings larger for unrestricted entry.

Second-row seatbacks can be adjusted through seven positions of recline. Three separate tether anchors are provided at the rear of the backrests for securing tether-style child safety seats.

To fold the second row seat a special four-bar linkage automatically cantilevers the bottom seat cushion both down and forward as the seat back is folded down to create a flat load floor. In contrast to some competitor's SUVs, releasing, lowering, raising, and re-latching the folding second-row seat are simple one-handed operations. Placing a child in the second row seating area or loading a grocery bag into the cargo area through the back door are, thanks to design ingenuity, simple tasks.

A convenient walk-in feature is provided at the right (curb) side of MDX's second-row seat. Lifting one lever permits the whole seat to slide forward on its tracks and the backrest to tilt forward, providing an entry path to the third row seats. Simply pushing the seat rearward again re-latches the seat in its rearmost position. The seat-tilt mechanism, step-in height, and the opening provided between the open second-row seat and the door frame are all sized for easy and convenient use by children. A hand-hold is also provided on MDX's rear side wall trim to ease passenger access to the third row seats.

MDX's third row is an occasional seat configured specifically for one or two children. A slightly elevated hip point height provides good forward visibility for third-row passengers while headrests are both height adjustable and removable. Like the second row, backrests can be reclined through six positions. Two tether anchors are provided for securing one or two tether-style child safety seats in the third row seats.

When not in use, either half of the third-row seat can be folded flat on a 4-bar linkage (similar to the second row seat) that brings it flush with the floor. Handles positioned at the top-outboard corners are accessible both from the rear doors and from the tailgate. This lift handle also releases each half of the seat so it can be raised or lowered independently. The third-row seat headrests can be stored in the cargo compartment located under the rear floor.

REMARKABLE STORAGE CAPACITY
Engineers configured MDX to handle an amazing range of contemporary family storage needs. In addition to the center console bin and beverage container holders, MDX has a long list of built-in features and the easy adjustment necessary to serve driver's of premium SUVs.

The hinged glovebox has capacity that is precisely twice as large as the Lexus RX300 box. It is also illuminated, lined with flocking material, and lockable. A motion damper allows a controlled, fluid opening motion -- preventing the lid from banging open against a front passenger's knees.

The front door pockets are purposely configured to hold maps, guide books, and road atlases while the rear door pockets are just right for sunglasses, small toys, treats, and bottled beverage containers. Armrests for the third-row seating area have small storage boxes covered by latchable lids. A rear under-floor compartment is ideally located for easy access through the open liftgate. Pockets stretched across the rear of the front bucket seats are ideal for stashing a variety of things for easy access by front-row and second-row passengers.

MDX's impressive cargo volume -- the single attribute that attracts most buyers to SUVs in the first place -- is, as you would expect, versatile and practical. Four-foot wide sheets of building materials slide in between wheel wells with ease -- an attribute not matched by MDX's direct competitors. With second- and third-row seats folded down, MDX offers 82 cubic feet of cargo space to swallow virtually whatever you may need to carry. No other competitor in MDX's class can match this surprising capacity. Only full-size truck-based models (such as the Ford Expedition and Chevrolet Tahoe) have greater cargo storage capacity.

A low load floor and seats that fold flat are the keys to versatility. To simplify conversion of the seats to a cargo area the third-row and second-row center seat belts easily detach from their floor anchors with a patented and simple-to-use mechanism. Six cargo tie downs are spotted strategically around the perimeter of the load floor to help secure objects susceptible to sliding or rolling. And since both the second- and third-row seats are split designs, six cargo/seating configurations are possible to suit carrying needs. Various accessory hardware is available from Acura dealers to safely and conveniently carry bicycles and other gear inside the vehicle and the roof rack (standard on MDX with Touring Package, optional on MDX) is useful for hauling skis, surfboards, or bulky camping equipment.

Inside, there's room for two to seven passengers and ample cargo. Thanks to the wide-opening liftgate and flat floor, large items, such as the box for a 32-inch TV will slide right into place for convenient transport. And it's possible to tote home 15, 3-cubic-foot bags of garden mulch without blocking outward vision. When the middle seating row is in use, there's still 22-cubic feet of space available, more than a full size car's trunk. And if it's necessary to use all three rows of seats, MDX still provides 7.6-cubic feet of space behind the third-row seat -- enough for eight paper grocery bags, four duffels and a cooler, or a full set of golf clubs.

A separation net is offered as a dealer-installed accessory that attaches to four built-in attachment points, two in the floor and two in the ceiling, and provides a separate area for cargo behind the second row of seats, along with a cargo line and liftgate apron that can be folded out over the rear bumper when the liftgate is opened.

SYNCHRONIZED HEATING, VENTILATING, AIR CONDITIONING
After analyzing competitive SUVs, it was clear to MDX engineers that significant strides could be achieved by offering climate control comparable to a luxury sedan instead of merely matching existing truck comfort standards. The resulting climate control system became a primary attribute of the Acura MDX.

The patented dual HVAC systems are normally linked in operation to improve heating and cooling performance by a full five minutes (17-percent) in comparison with use of the front system alone. The result is that comfortable conditions are achieved in every seating position in the shortest possible time after start up in hot or cold weather.

The ventilation control panel is positioned centrally on the instrument panel above the trip computer and navigation system display screen and consists of eight buttons to operate the front and rear heating and cooling units. One button controls full automatic operation in conjunction with up and down temperature-select buttons and a set-temperature display window. Alternatively, "Rear A/C Manual" button can be pressed to enable the second-row passengers control of the ventilation system in their area. Rear controls include a temperature-set knob, upper or lower air flow select buttons, and another knob to adjust fan speed.

Cooling and heating equipment for the rear seat is neatly packaged in the lower part of the center console. There's a blower capable of moving up to 392-cubic yards of temperature-controlled air per hour, a 2500-watt air-conditioning evaporator, and a 2800-watt water heater core. Concealed ductwork provides heated air to both second and third row passengers, and cool air to second-row occupants.

Total capacity of the linked front and rear systems is 19,000 BTUs which slightly exceeds the heating and cooling capacity found in the average American home. Tests by the MDX development team indicate that overall climate control performance is clearly best in class. And unlike some rear-, or roof-mounted HVAC systems MDX's equipment doesn't intrude on cargo or head room or interfere with the sunroof.

FLEXIBLE CENTER CONSOLE DESIGN
As a focal point of the interior design, MDX's center console is an extraordinarily versatile design. It's neatly integrated with the instrument panel design, it houses heating and air conditioning equipment for the benefit of rear-passenger comfort, and it provides a long list of storage and convenience features.

Additional details include a storage area for small objects ahead of the shift lever, two covered cup holders for front passenger use, and a climate-control vent and switch panel on the rear-most surface. For a luxury appearance, lower side surfaces are carpeted and woodgrain panels trim the forward horizontal surfaces. A mat in the bottom of the forward bin is removable for cleaning.

The main storage compartment lid is padded to provide a comfortable armrest surface. This lid opens either to a 95-degree position for access to the interior compartment or to a 180-degree position to act as a second-row serving tray. Both the lid and its hinge are engineered to withstand normal usage. Two cupholders and a wide depression to hold snacks are molded into the lid's inner surface.

Inside the storage compartment, a hinged top tray offers a convenient storage location for tissues, writing materials, or a cellular telephone. An access hole located in the rear corner of this tray provides a path for the phone's power cord to plug into a 12-volt power outlet below. Clearance is also provided to permit closing the top tray while the phone is in use. Below the top tray is a second large-volume storage compartment. A mid-level shelf is an ideal location for credit card or magnetic access (key) card stowage. The remaining volume is large enough to swallow either a home-size tissue box or up to 13 compact discs inside their jewel cases.

INSTRUMENT PANEL LAYOUT
Consistent with other Acura vehicles, the driver's cockpit is organized with the emphasis on ergonomics to avoid distractions from the task of driving. Exterior lighting and turn signals, cruise control, and moonroof controls are positioned to the left of the steering wheel to prevent operation by passengers, while wiper controls are mounted on a right-side column stalk. Radio and cruise control switches are positioned just below the horizontal steering wheel spokes for easy use. Secondary switches are spotted near the instrument cluster.

A three-dial instrument cluster conveys vehicle system information to the driver: engine rpm, vehicle speed, fuel level, coolant temperature, and shift-lever position. Back-lighting for the three-dial cluster avoids glare and provides an attractive appearance. An array of indicator lights is positioned at the bottom of the tachometer and at the top and bottom of the combination temperature gauge and fuel level display. The speedometer is marked in both mph and kph to a full scale reading of 140 mph / 225 kph.

CENTER DISPLAY SCREEN AND ACURA NAVIGATION SYSTEM
The centerpiece of the instrument panel is a large multi-function display screen. MDX models not equipped with the Acura Navigation System present trip computer, compass and HVAC information in this highly visible location. The seven-inch (diagonal) LCD screen is flat with a curved bezel. It displays instantaneous and average fuel economy, range remaining, compass heading, outside temperature, time of day, HVAC mode, air-conditioning compressor on or off, and fan speed. A trip button to the left of the display cycles between trip and mileage information. A separate button resets fuel economy, trip mileage, and elapsed time registers. There's also a slide switch to adjust display-screen brightness.

One of the few options offered on MDX is a factory installed DVD-based and satellite-linked Acura Navigation System. Similar in function to systems offered in Acura RL, TL, and CL/CL Type S models, this equipment receives Global Positioning Satellite (GPS) data. That information is combined with signals from an onboard inertial guidance system and information from a Digital Versatile Disc (DVD) database to pinpoint the vehicle's location and help guide the driver to selected destinations.

The 48-state continuous coverage is conveyed to the driver by both audio and visual cues -- designed to aid navigation without causing distraction. A moving map in combination with direction arrows, detailed street names, turning instructions, and driving distances are provided on the LCD touch control screen.

A picture-in-picture capability permits simultaneous display of a large-scale map with detailed turning instructions. The driver always knows the current position and a balloon function instantly reveals the address of any selected location on the map. Points of interest can be searched by inputting that destination's telephone number. The volume of voice guidance instructions can be adjusted through eleven settings and the audio system's front speakers are automatically muted when direction commands are issued.

A matte finish is used on the display screen to enhance legibility while resisting fingerprints. Only a few key strokes are needed to enter destinations and route calculations are made expeditiously. If desired, a route with up to five destinations can be pre-programmed. The moving map can be instructed to display fuel stations, restaurants, and automated teller machines (ATMs). The on-board DVD system contains not only maps of all major metropolitan areas but also freeway networks and a nationwide directory of 3.7-million points of interest, restaurants, hotels, ATMs, and a number of other categories. One new function introduced with MDX is the ability to track vehicle position by means of dots on the screen for those areas not covered by DVD map data -- especially helpful when driving off-road.

The same screen used for navigation also displays trip distance, average fuel mileage, remaining range (miles to empty), elapsed time, outside temperature, time-of-day, and HVAC setting information. Pressing an on-screen mode button varies the direction of air flow through the front climate-control system. Pressing an A/C button switches the A/C compressor on and off. The fan button selects from five speeds. Available trip information includes range to empty, trip mileage, elapsed time, and average mpg. A log of up to five trip histories is retained in memory.

Adjacent to the central display screen are two adjustable vent registers, a master light switch, a hazard switch, and a small control panel for managing the synchronized front and rear HVAC systems.

HIGHLY ENGINEERED CUP HOLDERS
MDX engineers conducted a major cupholder R+D program to maximize the new MDX's occupant-friendly factor. The first thing they learned was the daunting array of beverage containers in daily use -- rectangular juice boxes, 12-ounce cans, 20-ounce bottles, various-sized paper cups from fast-food outlets, insulated coffee cups, and bottled-water vessels galore. Ten beverage holders were designed into the MDX's interior to accommodate a variety of passenger needs.

Real innovation was necessary to accommodate as many different sizes and types of containers as possible and to securely retain them during stopping and cornering maneuvers. For example, pockets built into the bottom portion of the rear door trim are purposely deep to hold either a 20-ounce soda bottle or larger bottled-water containers. Cup holders molded into the armrest areas adjacent to the third-row seat feature notches necessary to accommodate juice boxes. Cup holders positioned near the center of the vehicle (two ahead of the storage console, two built into the console lid's inside surface, and two more integrated with the fold-down second-row armrest) have stepped bottom surfaces to grab and hold different-diameter containers. Front-seat cup holders are a three-tier design with a rubber lip to help restrain a teetering container. Third row cup holders are also a three-tier design, but without a rubber lip, while second-seat cup holders are a slightly shallower two-tier design.

STANDARD MUSIC SYSTEM
MDX sound systems are engineered for optimum performance and tuned specifically for this vehicle's acoustical characteristics. The standard system provides premium sound quality and clarity with an emphasis on the first and second seating rows. A head unit integrated into the center-dash architecture plays the AM/FM stereo, cassette, or the single-disc CD. A micro antenna positioned at a discreet center-rear location on the roof receives radio broadcasts. Switches mounted below a left-side steering wheel spoke allow the driver to alter play volume, choose another radio station, or select a different CD track without shifting attention from the road.

Four integrated 30-watt amplifiers and one 35-watt amplifier drive a total of seven speakers. A 16cm midrange speaker is mounted in each door. There's also a 2-inch tweeter in each front door and a 10-inch sub-woofer in the right-rear interior trim panel.

ACURA/BOSE MUSIC SYSTEM
The MDX with Touring Package is equipped with an Acura/Bose" music system that provides superb entertainment in all seating positions thanks to a more complete speaker array and extra amplifier power. The attractive head unit is curved in two directions to coordinate with the center-dash design. This system offers AM/FM, cassette, and a 6-CD in-dash changer. The steering wheel mounted controls described above also command the Bose" system.

A special six-CD changer function allows the Bose unit to conveniently store extra discs ready for playing without a separate magazine. Touching a load button once opens the changer's door to permit inserting one CD. Holding that button down facilitates loading up to six CDs. Since the door opens only during loading and eject operations, there's less likelihood that foreign objects will jam the mechanism. This sound system can select any desired CD track or shuffle through stored material at random to provide hours of audio entertainment.

The premium Acura Bose- sound system adds a rear-mounted 2.5-inch twiddler speaker to the array described above for a total of eight speakers. Four integrated 25-watt amplifiers drive the mid-range, tweeter, and twiddler units while a separate 100-watts amplifier is provided for the 10-inch sub-woofer.

INTERIOR ILLUMINATION
Overhead lamps are provided for all three rows of seating. An additional cargo light mounted to the tailgate provides ample illumination both inside the vehicle and on the ground for convenient loading at night. When the lamps are switched off by closing the doors or inserting a key in the ignition switch, they fade out over a six-second period. All power window switches are illuminated for convenient night-time operation.

KEYLESS SECURITY SYSTEM
To avoid interference from cellular telephone transmissions and pager towers, MDX's keyless security system communicates via FM (instead of AM) signals (Touring Package only). When doors are unlocked remotely, outside mirrors and the driver's seat automatically move to pre-selected memory positions. (Two fobs are provided to distinguish one driver in the family from another.)

The fob itself has three buttons. At the top, there's a large triangular-shaped button to command the lock function. A smaller round button with a raised nib for tactile identification commands the vehicle to unlock all doors. Operation of the locks is confirmed by an audible chirp. The third button at the bottom of the fob is recessed; pressing this "panic" button activates two loud trumpet horns to signal distress.

2001 Acura MDX - Safety

INTRODUCTION
The Acura MDX SUV is engineered to meet and often exceed all applicable safety standards. Safety, security, and accident avoidance are top Acura priorities. With that in mind, various systems &endash; body structure, chassis, driveline, passenger restraints &endash; interact positively to help the driver steer clear of hazards whenever possible and to enhance occupant protection in the event an accident is unavoidable.

An innovative Variable Torque Management (VTM-4) all-wheel-drive system is the key to sure-footed handling and straightforward controllability whether the pavement is dry or wet and slippery. Combined with MDX's four-wheel independent suspension, speed-sensitive power rack-and-pinion steering, and four-wheel-disc with Anti-Lock brake system, VTM-4 delivers best-in-class traction to enhance the driver's ability to guide an MDX safely out of harm's way.

To help safeguard occupants from injury when a collision is unavoidable, MDX provides multiple layers of protection. The computer-engineered body structure features front, side and rear crumple zones, a high resistance to offset and side impacts, and a well protected fuel tank. Extensive use of high-strength steel yields a robust safety cage surrounding passengers without incurring an awkwardly heavy curb weight.

All seating positions have three-point seat belts. Front seat belts are equipped with pretensioners and automatic load limiters that are activated in certain collision conditions. The MDX comes with standard driver's and passenger's front air bags. The dual-stage passenger's front air bag can deploy at the most appropriate of two rates depending on the severity of the crash. In addition, if the driver's or passenger's seat belt is not fastened, the air bag deploys at a lower collision speed to help offer more protection to the unbelted occupant.

The driver's and passenger's seats also feature side air bags mounted in the seat bolster closest to the door. The front passenger's seat is equipped with a system designed to disable side air bag deployment and prevent injury to a small child (or small-statured adult) if they lean into the side air bag deployment path. Once the child returns to an upright seating position, the side air bag will reactivate so it can deploy and protect the child in a side impact.

SAFETY STRUCTURE
MDX engineers used powerful computers more extensively than ever before to assure that this vehicle's safety cage structural design would perform well even before physical prototypes were built. Crash simulations helped reveal areas of the design that needed more &endash; and sometimes less &endash; reinforcement to absorb energy while resisting intrusion.

MDX has an especially robust floor construction to optimize both rigidity and resiliency. Two longitudinal rails run continuously from bumper to bumper. The rails are buttressed by a total of eight box-section crossmembers and two bumper bulkheads. This provides the strength needed to resist standard barrier impacts at the front and rear, offset crashes (wherein most of the load is applied longitudinally to one corner of the vehicle), and side impacts.

A four-ring shell-type safety cage is used to help protect occupants with A, B, C, and D pillars that run continuously to avoid intrusion during side impacts. To meet 2002 federal head-impact requirements, roof-pillar trim and headliner materials absorb energy and help reduce the likelihood of occupant head injury. Stiffeners inside the doors at the beltline provide a continuous horizontal connection between the first three pillars. Tubular beams are welded inside the doors at wheel height to provide additional intrusion resistance.

One quarter of the body structure &endash; longitudinal rails, floor crossmembers, pillar reinforcements, and bumper beams &endash; is made of high-tensile steel for maximum strength with minimal weight. A patent has been applied for the roof-mounted reinforcement used to secure the second-row-center passenger's seat belt.

MDX's fuel tank uses a highly puncture resistant six-layer high-density molded-polyethylene construction. It's located ahead of the rear axle and for protection, high-strength, box-section floor reinforcements help guard it from side collision damage.

The bottom line is best-in-class collision performance. Based on internal simulation and testing, the MDX is expected to earn five stars in federal government New Car Assessment Program (NCAP) frontal barrier tests and Side Impact (SINCAP) tests. A good rating is expected from the Insurance Institute for Highway Safety's offset barrier tests.

FRONTAL RESTRAINT SYSTEMS
Unlike some SUVs, MDX provides a three-point restraint system for all seven seating positions. A special roof-mounted reinforcement, positioned between the C and D pillars, serves as a rigid mounting point for the second row, middle passenger's shoulder belt.

All seating positions have three-point seat belts. Front seat belts are equipped with pretensioners and automatic load limiters that are activated in certain collision conditions. The MDX comes with standard driver's and passenger's front air bags. The dual-stage passenger's front air bag can deploy at the most appropriate of two rates depending on the severity of the crash. In addition, if the driver's or passenger's seat belt is not fastened, the air bag deploys at a lower collision speed to help offer more protection to the unbelted occupant.

The driver's and passenger's seats also feature side air bags mounted in the seat bolster closest to the door. The front passenger's seat is equipped with a system designed to disable side air bag deployment and prevent injury to a small child (or small-stature adult) if they lean into the side air bag deployment path. Once the child returns to an upright seating position, the side air bag will reactivate so it can deploy and protect the child in a side impact.

ADVANCED SIDE AIR BAG SYSTEM
Like other Acura products, MDX is equipped with seat-mounted air bags to help safeguard the driver and front passenger from side-impact injury. An innovative occupant position detection system is used to assure that the passenger's side air bag has a clear path for deployment. In the event a child (or a small-statured adult) is leaning into the deployment path of the side air bag, a seven-segment antenna system built within the backrest is designed to signal this condition to an electronic control unit (ECU) also located within the seat. The ECU then deactivates the side air bag from functioning and triggers a "SIDE AIR BAG" indicator light in the instrument cluster. After the front occupant returns to a normal seating position, the side air bag module automatically resumes full-functional status.

ANTI-THEFT ALARM SYSTEM
MDX has a standard keyless-remote entry system that locks and unlocks all doors and the rear hatch at the push of a button. To enhance theft protection, only one key lock mechanism is provided for the driver's door position. The same key fob used to lock the doors also activates the MDX's security system. In response to any attempt to enter the vehicle without the key fob or ignition key, the horn sounds, and the flasher lamps are activated. If need be, the alarm system can be triggered to summon help by depressing a "panic" button on the remote-keyless fob.

SECURITY/IMMOBILIZER SYSTEM
Imbedded within MDX's ignition key is an electronic microprocessor circuit that communicates with a receiver in the ignition switch to enable the vehicle's electrical systems. Forcibly vandalizing the ignition switch, hot-wiring, or attempting to start the car with a key lacking the microprocessor circuit will result in immobilization. Without proper key-to-immobilizer communication, the MDX will simply not start.

2001 Acura MDX - Quality & Manufacturing

INTRODUCTION
Typical of all Acura products, the MDX benefits from an integrated approach to designing manufacturing quality into the original plan for the vehicle. This approach results in a vehicle that is sure to achieve the legendary durability, quality and reliability that is the hallmark of all Acura vehicles. To achieve the specified targets for quality, the MDX team had to carefully consider the logical assembly of components as well as the effects of time and wear on each part and system.

The development team conducted testing on three continents and covered thousands of miles of testing varying from bitter cold to sweltering heat, adding in variables of high and low altitude environments, with full loads and a battery of tests that left nothing to chance. These tests confirmed that MDX will perform at its impressive levels for years to come.

The following are a few of the many areas that show exactly the type of attention to detail that typifies the design and engineering behind the MDX.

MINIMIZING NOISE, VIBRATION, HARSHNESS
A quiet interior is essential to any high quality vehicle. Towards that end, Acura engineers incorporated a host of design features and refinements aimed at blocking NVH from the passenger cabin.

All powertrain-related hardware is double isolated from the main body structure by use of rubber mounting systems. A perimeter-type front subframe supports the engine, transaxle, steering, and front suspension lower control arms. Two engine mounts are hydraulic designs with internal damping to provide excellent isolation throughout the broad range of excitation frequencies. An assortment of tuned-mass dampers attached to both the engine mounts and the subframe counteract resonance. A dual-path upper mount is used between each front spring and strut unit and the body structure.

The front axle half-shaft inner joints are designed with internal rollers that minimize friction. A two-piece tubular propeller shaft is used to transfer torque with no susceptibility to whip or vibration. A dynamic damper positioned inside the front tube is tuned to cancel out vibration at cylinder-firing frequencies. The rear drive unit is supported by three rubber mounts in a second subframe, which is in turn attached to the body structure through four widely spaced rubber mounts. Rear coil springs are insulated from both the body and the rear suspension hardware by means of upper and lower rubber pads.

MDX's fuel tank has rounded corners and internal baffles to avoid sloshing noise. Various subsystems -- the fuel vapor canister, the assembly, and the ABS modulator -- are rubber isolated from the body to block any sympathetic NVH contribution.

MINIMIZING NOISE, VIBRATION, HARSHNESS
The engines high volume intake and exhaust systems are engineered for non-restrictive but quiet flow of fluids through the engine. Just aft of the point where left- and right-bank exhaust flow join, a corrugated flex pipe is positioned to permit quiet movement between the engine and the remainder of the exhaust system. A large pre-chamber muffler near the middle of the vehicle is glass-filled to absorb high-frequency exhaust noise. The high-volume silencer near the rear bumper has dual outlets to ensure exhaust flow requirements during full throttle acceleration.

Extensive sound deadening is used within MDX's body structure. Melt sheets -- a mixture of asphalt and reinforcement material that bonds to surfaces in the paint ovens -- cover virtually the entire floor of the vehicle from the vertical dash panel to the liftgate sill. Additional sound-deadening material blankets the dash panel and the rear of the hood. Molded rear fender liners help quiet road splash and tire noise. To create a noise barrier at the base of the A, B, and C pillars, expanded foam fills these cavities. This foam is expanded by the heat of the paint-curing ovens, noise from the floor area is blocked from being transmitted inside the pillar cavities to the interior compartment.

Special recycled textile absorption blankets are attached to the underside of the instrument panel and the sides of the center console.

Design of the door mirrors is especially sensitive to wind noise. To avoid whistles, an overlapping tongue-and-groove arrangement is used between inner and outer mirror base components. Sponge material between the base and the door surface eliminates the possibility of gaps in that area. The molding to base interface is also a zero-gap design.

Additional weatherstrips are positioned in critical window frame to pillar gaps to help maintain smooth air flow down the side of the vehicle.

The bottom line is a net lack of road, powertrain, and wind noise inside the passenger compartment. In competitive tests, MDX is comparable with the best luxury-class SUVs in overall NVH performance.

QUALITY CRAFTSMANSHIP, QUIET INTERIOR
The all-new Acura MDX is the first sport utility vehicle designed with a no compromise engineering philosophy. MDX delivers fresh styling, unmatched versatility, car-like driving exhilaration, class-leading safety and environmental responsibility while also upholding Acura's well established reputation for outstanding value. Acura customers expect best in class quality. Towards this end, MDX has the refined attention to detail lacking in several of its luxury SUV class competitors.

Body gaps are best in class by an impressive margin. Exterior design is clean, functional, and well proportioned. Adornments are elegant and tasteful. Door jams are neatly finished. MDX will easily set a new standard for quality craftsmanship in its class.

CHROME DOOR HANDLES
MDX's pull-type door handles are fully chrome plated for a luxury look and feel. Clearance pockets behind each release handle are generously sized to provide room for gloved hands and to avoid ring and fingernail scratches.

TIGHT, CONSISTENT PANEL GAPS
To minimize construction tolerances, MDX's doors are attached to the car by rigid bolts that pass through zero-clearance hinge holes. Doors are made of high-strength galvanized steel for dent resistance. Front mudguards are provided to deflect rocks and debris and rear mudguards are available as dealer-installed accessories. Lower door surfaces are painted with a soft primer that's especially resistant to stone chips. Seals that extend from the lower edges of the doors to the sill area block the build up of dirt and debris that would otherwise soil clothes legs during entry and exit from the vehicle.

Panel gaps are consistently tighter than comparable dimensions seen in competitive makes. For example, MDX's hood-to-headlamp gap is less than a third of what's common in the Mercedes ML320 and less than half the width of the Lexus RX300's gap. Most MDX gaps are between 0.12- and 0.18-inch compared to 0.18- to 0.3-inch in the Lexus and 0.2- to 0.37-inch in the Mercedes. To permit a tighter fit between rear quarter window and the adjacent quarter panel, a beveled edge is used on the glass.

Seals and covers are positioned in door jams and sill areas to mask assembly welds. In the liftgate opening, the trim has a clean appearance that's not marred by the visible bumper clips used by some competitors. All interior trim is retained with hidden fasteners. Front and rear wipers are smooth, single-piece designs for a clean look.

Door mirrors have blue-tinted glass to cut glare at night. Electrical heating grids can be activated by a switch near the remote mirror control pad to clear frost and fog from the mirror surface.

Side and rear window glass is deeply tinted for privacy and to keep the interior cooler during summer months.

MANUFACTURING
The MDX will be built at Honda of Canada Manufacturing in Alliston, Ontario, near Toronto.