Been a long time….: Cadillac redefines itself

Automotive Design & Production,  July, 2003  by Gary S. Vasilash

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With the introduction of the SRX sport utility and the XLR roadster, Cadillac is proving that it is on the road to redefining itself in a more substantive way than just through the clever use of a Led Zeppelin song in its advertising. But just watch it move.

Nowadays, upscale crossover sport utilities are becoming the norm in premium showrooms. It all started in 1998 with the Lexus RX 300 (which has since become RX 330); it has been joined by a host of other vehicles. One of the characteristics of these SUVs is that they tend to be less truck-like in form than their body-on-frame counterparts. Sometimes it is a matter of their simply exhibiting smoother exterior lines. Or (think of the Volvo XC90) they look like, well, station wagons.

In the world of SUVs in general, General Motors is doing well, with an assortment of vehicles: everything from the Suzuki-based Chevy Tracker to the Suburban-based Cadillac Escalade. The Escalade is certainly a phenomenon, helping drive the age demographic down: according to Cadillac statistics, the average age of an Escalade buyer is 50, which is more than a decade younger than the average buyer of the brand.

With the burgeoning crossover SUV market, Cadillac executives set about to develop another variant off of the Sigma platform, the same platform that is used for the CTS, the vehicle that introduced the Art & Science design theme to the world with the pounding backbeat of John Bon ham on Led Zeppelin's 'Rock and Roll.' There is something to be said for not being first in this body-on-frame-integral luxury sport ute field. You're able to see what others have done, and learn from their delights and their demerits. It is clear that the people at Cadillac went to school on the competitors. They've engineered a vehicle that has a design and content quotient that will undoubtedly have the competitors going back to it as a touchstone.

The SRX has an evident familial relation to the CTS sedan. This is not merely a function of the designers taking the body panel direction that was originally inspired by the surfaces and angles of a stealth fighter. (There were some doubts about the CTS's market potential, yet in its first year it sold 7,876 more units than the 30,000 that it was expected to. That, you may think, is not all that big a number, until you calculate that it is 26% above the target.) There is more than a superficial relationship between the two vehicles. There is the aforementioned fact that they are both based on the GM Sigma platform. They are also both manufactured at the Lansing Grand River Assembly Plant, the 1.9-million-ft2 North American showcase for the GM Global Manufacturing System. In fact, both vehicles are produced on the same line.

What's a "Sigma"? One might assume that the CTS and the SRX are dimensionally the same size, given that they are based on the same platform. And one would be wrong. The SRX has a 116-in. wheelbase. It's 195-in, long (longer than either the Lexus RX 330 or the target, the BMW X5) and 72.6-in, wide. The CTS has a 113.4-in, wheelbase. It's 190.1-in, long and 70.2 in. wide. So what's the "Sigma platform" mean? Jim Taylor, vehicle line executive for Sigma, explains that there are at least a couple of ways to look at that. For one thing, there is a dimensional quotient. Although there is a disparity in size between the two existing vehicles, they are of an overall 'footprint" that can be accommodated by Lansing Grand River: the tooling and equipment can handle vehicles within a designated size. Taylor goes on to note that in addition to having common locating points, the Sigma vehicle process (i.e., are put together) in a like manner. For example, the engine modules attach the same way on the line whether it is a sedan or a sport ute.

Another aspect of the platform relates to what Taylor refers to as "the bits," the elements that are used to assemble a vehicle and consequently provide its character. He cites the all-aluminum suspension components that are used for Sigma vehicles. They are affordable in the price category that these vehicles retail at (e.g., the SRX starts at $37,995). And Sigma uses more ultra high-strength steel than other platforms in the GM system (e.g., the Epsilon platform that's used for the forthcoming Malibu); that steel is comparatively expensive.

The SRX is either a five- or seven-passenger vehicle, depending on whether the optional third row is included. Either way, it provides utility in the sense that if the seats are folded flat there is space for stuff--69.5-ft.sup.3]--and there is trailer-towing capability (a maximum of 1,000 or 3,500 lb., depending on options). It is a sporty sport utility vehicle in that it can be ordered with the 4.6-liter Northstar V8, which provides 320 hp 6,000 rpm and 315 lb-ft of torque at 4,400 rpm. (The base engine is a new 3.6-liter engine that also has variable valve timing; it produces 260 hp 6,500 rpm and 252 lb-ft of torque a 2,800 rpm.) Both engines are mated to five-speed automatics. The weight distribution of the rear-wheel drive vehicle (the SRX is also available with an all-wheel-drive setup) is approximately 50:50, so with the long wheelbase, the vehicle handles exceedingly well on the road... especially if the vehicle is ordered with the Magnetic Ride Control system, a Delphi-developed system that uses magn etic fluid for split-second suspension control (sensors measure the road surface in one-inch segments even when the vehicle is traveling at 60 mph and adjusts the stiffness of the suspension accordingly), a system that was first introduced on the Corvette... [second verse]