The Acura MDX™ was created to define a new era in the evolution of luxury sport utility vehicles, treading beyond the limits of existing SUVs in terms of handling, packaging efficiency and environmental impact. The MDX was developed with the 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. As the development process progressed, an additional development goal was added - furnishing the vehicle with an array of cutting edge features that effectively "defeat winter" for its driver and passengers - limiting the harsh effects of the cold winter months on MDX occupants.
These development goals encompass all areas of development, even when they are seemingly at odds with each other. For example, a 240-horsepower, 3.5-liter V6 engine -more performance than any 6-cylinder SUV in its class - powers the Acura MDX yet it meets ultra-low emissions vehicle (ULEV) standards in all 50 U.S. states. MDX also achieves 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 many 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 as a Multi-Dimensional Cross Trainer - an athlete that excels on many playing fields.
For the 2002 model year, the MDX comes in four new exterior colors and receives a variety of enhancements aimed at reducing Noise, Vibration and Harshness (NVH) for an even quieter, more comfortable ride. These enhancements include thicker windshield glass, the addition of sound damping roof lining and new "diffsuer" side mirrors.
PERFORMANCE ATTRIBUTES OVERVIEW
Outstanding performance has always been a fundamental Acura character trait. The development of Acura's first in-house designed and engineered SUV presented the opportunity for the engineers to sidestep the standard shortcomings of products already on the market and begin with a fresh approach to the SUV equation. That approach was to create the first no-compromise SUV - melding attractive design, unmatched versatility, driving exhilaration, social responsibility, and value in one neatly wrapped package.
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 in each of the 50 U.S. states, and 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 for balanced, all-around performance.
MDX's 4500-pound boat towing package (3500-pound for trailers) 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 wide-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 a 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 vehicle's braking system to match its acceleration - 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 4-channel 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 responsive 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. 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 fine-tuned suspension geometry. Low roll centers combined with large stabilizer bars provide progressive, predictable cornering response and excellent stability at the limit of adhesion. Lightweight materials - 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 configurations 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 low in emissions - 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.
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 improve handling precision, 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. Every MDX achieves stringent ULEV emissions levels - 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 highway in EPA tests places it ahead of all luxury SUVS in fuel economy and proves that powerful SUVs can 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 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 off road excursions, 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 on-road 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 eight 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.
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 the MDX 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
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 proactively 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) and there is 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 move the shift lever to first, second or reverse and then touch the VTM-4 lock button on the dash. With the lock mode engaged, VTM-4 "locks" the rear axle to provide maximum power transfer to each rear wheel. As speed increases above six mph, the system automatically reduces the lock effect to the rear axle. By 18 mph, the system reverts to front-drive.
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 insight, 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 and Acura's VTM-4 all-wheel-drive system. 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 when one side of the vehicle is on ice and the other side is on dry pavement) does not tend to pull the vehicle in one direction or the other.
Total roll stiffness is equitably distributed so that 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. 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 steering 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 its 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. Conversely, 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 lower surfaces that are 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.
New for 2002, the MDX features an intermittent rear windshield wiper. 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 kept 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.