INTRODUCTION
To pursue a new direction in the luxury SUV segment, Acura envisioned
MDX as the first SUV to combine a car-like ride and handling with a
family-sized SUV interior. By avoiding some of the compromises that
other manufacturers have accepted, MDX combines dynamic performance,
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 vehicle's 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, 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. 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 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, and continues with an 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 produce a vehicle that is as pleasing to the eye as it is to drive.
To make this product a significant leap forward in environmental awareness and, ultimately, the intelligent SUV choice for sophisticated buyers, MDX designers shaped the vehicle's exterior to minimize aerodynamic drag and specified the use of recycled materials where possible. The aerodynamically efficient shape results in low wind noise and improves highway fuel economy for this environmentally conscious vehicle.
The personality for the MDX is rugged yet sophisticated and refined, practical, yet enjoyable. MDX designers mapped out a fresh set of proportions to meet the development goals, incorporating a full-size interior into a mid-size-SUV's exterior space. That meant stretching exterior width to maximize the available interior space and 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 meets 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
assuring 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 precision 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 help 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.
Much 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 vehicle's 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, 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 areas (doors and windows), and the doors are made using laser-welded tailored blanks. This innovative door design uses higher-gauge steel in high-stress areas and lighter gauge 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 passenger's upper-shoulder belt.
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 is 30-percent stiffer than the Lexus RX 300 in this particular area.
The use of high-strength, closed-section steel bumper beams enhances occupant safety and decreases damage sustained during rear end collisions. In low-speed crash tests conducted by the Insurance Institute for Highway Safety, the MDX received the best scores of any midsize SUV tested.
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.
AERODYNAMIC DESIGN
A low aerodynamic drag coefficient was essential to achieving MDX's
goal of best-in-class highway fuel efficiency. Toward that end, MDX
was styled with a sloped and tapered front-end. The windshield is
tilted at 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 attractive and
aggressively styled halogen lamp assemblies. Following the lines of
the grille, the lamp assemblies wrap around to the forward edge of
the front fenders, providing a natural transition from the vehicle's
front to its side. A clear outer lens provides a clean look and
allows smooth air flow around the vehicle's front corners. The
innermost lamp is for high-beam illumination; and uses a round
reflector. In the middle position, a multi-faceted,
rectangular-shaped low beam provides 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 fog lamps 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 when backing up.
GLASS
Excellent visibility, giving drivers a commanding view of the road
ahead and passengers a pleasant open feeling, was a high priority in
designing the MDX. To that end, 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. Squaring the rear edge of the outside rear view mirror's mounting base benefits air flow patterns and reduces 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 be unlocked with either a remote keyfob or the interior switch. Reinforced steel guards have been installed to deflect break-in tools away from the front door lock rod and latch mechanism. Double thick 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. Rear lock rods are positioned behind the center sashes so they are inaccessible from outside the vehicle.
REAR-VIEW MIRRORS
The 2002 MDX features "diffuser" side mirrors that smoothly channel
air between the mirror and the side window glass resulting in less
wind noise and improved aerodynamics.
The use of blue-tinted side mirror glass greatly reduces sun and headlamp glare to the driver. Owners of the MDX with the Touring Package, receive two keyless remote key fob units that can be 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 the vehicle's window washer and wiper systems. The
intermittent rear wiper allows the driver to match wiper speed to
various levels of precipitation. 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.
For the front windshield, single-piece wiper arms are used. Fluidic nozzles are fitted here for several reasons: they have a large orifice that covers more surface area, they are less likely to clog than a conventional nozzle and they clean the windshield with fewer wash cycles.
ROOF RACK
Designed to accentuate both the styling and utility of the MDX, the
integrated design of the roof rack (standard on Touring models,
available as an option on standard models) consists of two fixed
cross bars that mount in the rain channel of the roof. For 2002, the
front cross bar was moved rearward to reduce wind noise and improve
aerodynamics. The cross bars are designed to carry items weighing up
to 150 pounds when properly loaded. 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 are made of
plastic-sheathed steel for high stiffness and durability. The
adjustable end stays are sturdy zinc die-castings covered with
stylish trim. 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 excellent reception, with the security
and enhanced appearance roof-mounting as opposed to more common
fender or A-pillar type mountings.
SPARE WHEEL AND TIRE
A compact spare tire is carried under the rear load floor and can be
lowered by turning a hex-head mounting 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.
MOON ROOF WIND DEFLECTOR
Wind noise can be annoying when the sunroof is open in a vehicle with
large interior volume. MDX engineers solved this problem by providing
a 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 the wind deflector,
the MDX is one of the quietest SUVs on the market with the moonroof
in either the open or closed position.