INTRODUCTION
To pursue a new direction in the luxury SUV segment, Acura designed the 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 and complements 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 design to complement a functional and versatile interior space. The lines create a natural flow from front to rear, as if MDX was sculpted from one solid piece, reinforcing 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 2004 MDX receives a number of styling changes that accentuate and enhance the aggressive styling of the previous model. The front fascia was redesigned with a sharper, more tapered look and an integrated chin spoiler was applied to reinforce the muscular stance and direct air under the front of the vehicle. The rear fascia has also been redesigned and includes a new more sophisticated taillight assembly, and dual exhaust tips. Satin chrome finish has also been applied to the front and rear trim.
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.
MDX designers mapped out a fresh set of proportions to meet these 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 rigorous design requirements. 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 to achieving balanced and predictable handling and assuring that the ride is smooth and quiet for the life of the vehicle. High levels of torsional rigidity help provide the MDX with precise handling by minimizing any unwanted movement of suspension components and changes in geometry.
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. Additionally, both the rear floor and wheel house are reinforced for increased rigidity.
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. Reinforcements placed on the right and left of the tailgate opening enhance body rigidity even further. The use of high-strength, closed-section steel bumper beams enhances occupant safety and decreases damage sustained during rear end collisions.
All this works together to make the 2004 MDX one of the safest SUVs on the road. In internal frontal and side impact crash tests conducted according to guidelines used by the National Highway Traffic Safety Administration (NHTSA) and the Insurance Institute for Highway Safety (IIHS), the 2004 MDX achieved 5-star ratings.
AERODYNAMIC DESIGN
A low aerodynamic drag coefficient was essential to achieving MDX's goal of outstanding highway fuel efficiency. Toward that end, MDX was styled with a sloped and tapered front-end which is sharper and narrower for 2004. The windshield, which now features acoustic glass, 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 coefficient of drag of the MDX is 0.36. As a result, highway fuel efficiency is an impressive 23 mpg.*
LAMP DESIGN
Front-of-vehicle illumination is integrated into attractive and aggressively styled projector-type halogen lamp assemblies that offer better superior illumination. Following the lines of the grille, the redesigned 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 rectangular reflector. In the middle position, a projector-style, circular-shaped low beam provides for excellent near-vehicle illumination. Twin amber stripe parking and turn signal lights occupy the outermost position of the lamp assembly.
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.
The taillight assembly has been reconfigured for 2004, featuring a sportier, sophisticated design. The direction signals have been separated from the back-up lamps previously housed in the middle section of the assembly and are now located at the top. The dark chrome upper bucket surrounding the bulb matches the look of the newly designed headlights, providing a uniform look. The isolated reverse lights with circular reflectors remain in their central position, dividing the combination stop/tail-lamp display, which has been lowered slightly to provide a sportier look. The reflector keeps its position at the bottom edge of the assembly.
*Preliminary EPA mileage estimates determined by Honda. Final EPA mileage estimates were not available at the time of printing.