Under the skin of the 2005 Cadillac STS

Automotive Design & Production, June, 2004

When Cadillac pulled the covers off its 2005 STS at the New York Auto Show, the big news was the base price: $40,995 for the V6 model, $47,495 for the V8. The switch to rear-drive from front-drive, with all-wheel-drive an option on V8 models, was a close second. But there's a lot more to the new STS than meets the eye. Specifically:

* It's built on the Sigma platform along with the CTS and SRX, and approximately 30,000 will be sourced from the Lansing Assembly Plant.

* A one-piece hydroformed rail runs from the A- to C-pillars, with structural foam used in the A- and C-pillars and along the windshield base, rockers and rear wheel kick-up.

* The front suspension has aluminum upper and lower control arms, knuckles and body interface brackets.

* Aluminum is used for the upper control arm and knuckles in the rear, and for both the front and rear brake calipers.

* Jim Federico, chief engineer, Prestige Vehicles, says the STS is 5 dB to 10 dB quieter than the smaller CTS due to structural integration of the longitudinal rails and crossmembers.

* The windshield and front side windows are laminated to reduce noise.

* Eucalyptus wood is used on the steering wheel, instrument panel and door panels, and spray-skin urethane covers the instrument panel which sits on a two-piece magnesium cross-car beam.

* Dual density foam is used in the front and rear heated, ventilated seats.

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* The lower wire mesh grille is electro-plated and polished.

Bob Lutz, GM's vice chairman, insisted the roof be lowered one inch, the wind-shield and backlight be given more rake, and the tumblehome increased. Plus, he wanted it done without losing any interior room. Kip Wasenko, who was the chief designer on the STS, took the opportunity to massage the design and make it more exciting: "I wanted it to be refined and sophisticated, crafted and tailored, and we spent a lot of time on tightening the gaps and radii. But," he says, "it was worth the effort, even if my guys wanted to kill me at times."