New Acura MDX Slims Down
The mid-luxury auto makeremployed a variety of measures now common in the industry, and some that are not, to get the MDX all-wheel-drive model down to a fighting weight of 4,270 lbs., besting the Audi Q7.
June 28, 2013
DETROIT – Acura put its MDX large cross/utility vehicle on a diet for the ’14 model year.
The third-generation CUV drops 275 lbs. (125 kg) in the all-wheel-drive Tech grade from its predecessor, despite a 2-in. (5-cm) gain in overall length.
The reduced weight helps improve the MDX’s fuel economy at time when U.S. government standards are moving toward a fleet average of 54.5 mpg (4.3 L/100 km) by 2025.
Acura employed a variety of measures now common in the industry, and some that are not, to get the MDX down to 4,270 lbs. (1,937 kg). The CUV now has the lightest curb weight among other AWD V-6 competitors, including the Audi Q7, which is 963 lbs. (437 kg) heavier, MDX chief engineer Jim Keller says.
Helping the new Acura CUV shed pounds is its dedicated architecture. Keller says the underpinnings of the first two generations of the MDX, the ’01-’06 and ’07-’13 models, were based on Honda light-truck platforms, whose roots traced back to the second-generation, late-’90s Odyssey minivan.
“A lot of core, fundamental needs for a luxury SUV were baked into the platform from the beginning, and that allowed us to better meet all of the conflicting targets we set for this vehicle,” Keller tells media during a ’14 MDX briefing here.
The biggest weight loss comes from the body-in-white, which dropped 123 lbs. (56 kg) from the ’13 model. Acura engineers achieved this by more than doubling the body’s high-strength steel content, from 25% to 59%.
Individual elements of the body-in-white that are lighter for ’14 include the steering-hangar beam, now a single die-cast piece made of magnesium and 7.5 lbs. (3.4 kg) less than the ’13 model’s aluminum beam. The door ring now is a hot-stamped single piece.
“Other people are doing hot-stamping; (it’s) one of those technologies auto makers are all applying,” Keller acknowledges. “But typically, hot-stamping is done with separate stampings that are joined together as an assembly. In the MDX, this whole structure is now one complete assembly. It is stamped in the tool in red-hot temperatures, then heat-treated.”
The MDX door ring, supplied by Magna's Cosma group from its plant in Eagle Bend, TN, not only is lighter but more rigid, he says, improving the chances for front-seat passengers to open the door and step out of the vehicle in the event of a front-offset crash, something Insurance the Institute for Highway Safety now is testing according to its latest set of standards.
In a video of a ’14 MDX undergoing a front-offset crash test, the structural deformation stops ahead of the A-pillar. “There’s not even a wrinkle in the door skin,” Keller notes, saying Acura expects to pass the IIHS test, as well as receive an overall 5-star score for the new MDX from the National Highway Traffic Safety Admin.
Other weight savings on the’14 MDX include the front and rear subframes that are 15 lbs. (7 kg) lighter; rear suspension that shaves 26 lbs. (12 kg) and heating, ventilation and air-conditioning unit that weighs 10 lbs. (5 kg) less than before.
The rear suspension adopts a multilink design, with springs over dampers, from the ’13 model’s trailing arm and separate spring and damper setup, Keller says. The HVAC unit now is one integrated piece with a single blower, compared with the two separate blowers for the front and rear passenger areas in the last MDX.
Seats typically are among the heaviest components in a vehicle, and Keller says the MDX seats dropped about 44 lbs. (20 kg) thanks to the use of laser welding. “(With) laser-welding, you’re able to do a continuous bead of welding, instead of bead or spot welds where you’re stitching (the welds) together.”
The ’14 MDX is on sale now at U.S. Acura dealers.
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