NVH Chief Concern for GM Engineers on ’08 Chevrolet Malibu

By James M. Amend

MILFORD, MI – Ask a General Motors Corp. engineer which aspect of the redesigned ’08 Chevrolet Malibu sedan really gets his blood pumping and odds are he’ll say it’s the lack of noise, vibration and harshness.

Sexier attributes can be found on the new model, such as a lively 252-hp 3.6L DOHC V-6 with variable valve timing mated to a fuel-efficient, 6-speed automatic transmission – a combination GM first used on the award-winning ’07 Saturn Aura
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But GM clearly has given extra attention to making the ’08 Malibu’s cabin quieter and its ride more refined, which portends a pleasant surprise to consumers cross-shopping the Toyota Camry and Honda Accord, says Mike Meloeny, chief engineer for GM midsize vehicles.

“We’re real proud of what we accomplished with NVH because it so important to the segment, and it is such an extremely and brutally competitive segment,” Meloeny says during a recent media backgrounder here for the ’08 Malibu.

“People in the midsize segment want an upscale-feeling car, but they don’t want to pay for it,” he adds.
To meet this challenge, the decision was made to dampen the Malibu’s mechanics and provide the sort of atmosphere car buyers expect in a larger, more-expensive vehicle.

Engineers started with the chassis, strengthening and lengthening the same Epsilon-based global midsize vehicle architecture that underpins the Aura and Pontiac G6.

Exterior design forgoes generic styling that typifies midsize segment.

“We got the engine out in front, instead of in your lap, but we also stiffened the engine cradle so it wouldn’t twist or resonate with the exhaust,” Meloeny says.

The auto maker used liquid spray-on sound deadener, laminated steel and composite wheel liners to further deaden noise from the chassis.

Engineers also concentrated on dampening noise from the Malibu’s 4-cyl. engine, a 2.4L DOHC setup that delivers 169 hp and is a lock to be the car’s most popular mill. Because GM’s 4-bangers are not known for their pleasant acoustics, engineers added nine tuners and resonators.

“They’re all geared to knock out the nodals in the induction system,” Meloeny says.

GM mates the 4-cyl. to a familiar 4-speed transmission, for now. But in a segment-first, the auto maker will provide a 6-speed gearbox to the engine by the end of first-quarter 2008.

Other noise-reduction targets included the vehicle pillars, where GM added extra baffles, and also the rocker panels, which received baffles as well as a sound-dampening coating. Engineers even borrowed the laminated “quiet glass” found on the Aura.

GM’s efforts to make the new Chevy Malibu seem more expensive – the highest-trim-level LTZ version will start in the upper-$20,000, GM product chief Bob Lutz says unofficially – didn’t end with NVH.

The auto maker also sheds a longtime bugaboo by upgrading Malibu’s interior with better materials, such as a cast-skin material on the instrument panel.

Additionally, the ’08 model will offer 2-tone color combinations, a Malibu first that wowed critics at January’s North American International Auto Show in Detroit.

Other interior upgrades include a wood-grain element, optional suede-trimmed seats and black-chrome accents on the LTZ trim line. A chrome “Chevrolet” sillplate provides a particularly thoughtful touch on LTZ models.

Outside, the Malibu’s exterior design forgoes the generic styling that typifies the midsize segment for one that tries to communicate a longer, more stable wheels-to-the-corners look, while round taillamps pay tribute to its sporty Corvette stablemate.

Interior takes advantage of upgraded materials and for first time offers 2-tone color combinations.

Up front is the dual port grille now characteristic of all Chevrolet vehicles. Understated bright work furthers GM’s case for an upscale look on the Malibu.

GM engineers like to think they’ve achieved a balance between ride and handling on the new Malibu that laps the competition. A 4-wheel independent suspension gets McPherson struts up front and a multi-link setup in the rear.

The front suspension takes advantage of aluminum control arms to smooth out the bumps, while the rear suspension gets monotube, or twin-tube shocks, depending on the model.

Hydraulic ride bushings and body-control damping measures keep drivers in touch with the roadway without sacrificing comfort, GM says. Available wheel sizes range from 16 ins. to a segment-best 18 ins.

GM employs variable electric power-assist steering on 4-cyl. models, while 6-cyls. get a hydraulic assist. The auto maker characterizes response from both systems as “precise and immediate.”

The all-new ’08 Malibu will need all the inspiration GM engineers have provided to successfully compete in a crowded segment where Toyota Motor Corp. and Honda Motor Co. Ltd. continue to carry the most clout among consumers.

Not only does Chevy’s new entry have to measure up to the all-new Camry launched last year but also a redesigned ’08 Accord that’s already drawing media raves.