Hush: the Buick LaCrosse

Automotive Design & Production, Dec, 2004 by Gary S. Vasilash

Back in 2001, when Buick designers and engineers were working on what would become the replacement for not one sedan but two--the Regal and the Century--Bob Lutz took a look at what they were doing (like engineering a driver's interface that was largely based on voice-recognition technology with a steering wheel arrayed with so many buttons--to be used in the case that the voice system got hiccoughs--that Lutz describes it as "looking like a PC keyboard")--and he said that they needed to seriously rethink what they were doing. They were looking for something that would make Buick distinctive in vehicle design. They figured that advanced technology would do the trick. He gave them an alternative direction: create a car that is as quiet as anything not merely in its class, but even at a price point above. And so the engineers set to work to accomplish that, as the marketing folks came up with a term to describe what the engineers were providing: "Quiet Tuning." And the first sedan that is described as having it is the '05 LaCrosse, a midsize car that's meant to take on the likes of the Camry and the Accord but with the levels of refinement and attention to detail that one might expect from a Lexus or an Acura.

A big part of the Quiet Tuning approach is through the implementation of various materials to deal with noise. Vehicle chief engineer Ed Hufnagle says that there are essentially three ways they're dealing with sound:

* Reduce it at the source

* Block it

* Absorb it.

[ILLUSTRATION OMITTED]

To accomplish this they've deployed things including:

* A large sheet of a deep-drawn steel laminate (Quiet Steel from MSC) for the front-of-dash area (a.k.a., the firewall)

* Laminated glass for the windshield and front side glass

* Acoustical engine covers

* Forged steel crankshafts (said to be quieter than those cast and machined)

* Structural aluminum oil pan

* Hood insulator pad

* Baffles in the roof pillars

* Thicker carpeting developed with Collins & Aikman

* Extensive foam in pillars

* Plenty of melt insulation.

But while they've worked to make the vehicle quiet, they didn't want to make it seem as though people were driving on a couch. So they took the suspension components from the Regal/Century and then retuned about 80% of them. So, for example, the constant-rate front springs are 20% stiffer than on the previous models, as is the case with the variable-rate springs in the rear. But there are new bits, as well, such as a new front strut mount that provides a reported 2X damping increase compared with previous designs (the LaCrosse represents the first application of this design on a GM midsize car ... which means that it probably won't be the last). The rebound dampers are 40 mm tall; they are 10 mm on the Regal/Century. The jounce bumpers are also longer, 85 mm versus 65 mm. The basic architecture of the suspension: MacPherson strut coil-over-spring front and trailing arm/tri-link rear.

There are two six-cylinder engines available. There is the top-of-the-line 3.6-liter VVT (continuous variable valve timing) that provides 240 hp @ 6,000 rpm and 225 lb.-ft. of torque @ 2,000 rpm. This is one of GM's so-called "high feature" global engines. Used in other vehicles, it marks the first application in a front-wheel-drive vehicle. The other LaCrosse engine (standard on the entry and mid vehicles*) is the 3800 Series III 3.8-liter engine, which is an older architecture that has been improved with things like electronic throttle control. Both engines are held by a new all-aluminum engine cradle (which helps contribute to improved engine isolation--as in concerns for both noise and handling); both are fitted to the Hydra-Matic 4T65-E electronically controlled four-speed.

Stylistically, the car, which is said to be "the new face of Buick," resembles in many ways its predecessors. However, unlike the Buicks of the recent past, the tail lamp is not a single cross-car strip, but simply at each of the corners. Unlike Buicks of the more distant past, the outer sheet metal doesn't have portholes along the side. Word is that Bob Lutz had had the platform team look into the price of adding the portholes onto the vehicle that was already designed without them; the cost was prohibitive. When describing the inside, Buick designers and executives throw around the word "craftsmanship" and tend to point to the French seam sewing pattern on the seats. The plastic wood (burl pattern) is said to appear more like wood than plastic. There is a sense of spaciousness that is helped by lowering the IP hood in front of the driver some 3 in. The vehicle is available with a six-passenger configuration, which does away with the center console and puts the gear shift lever on the steering column.

*The vehicle is available in three trim levels. There's the CX at $23,495, the CXL at $25,995 and the CXS at $28,995 (all including the $660 destination costs).

By Gary S. Vasilash, Editor-In-Chief