Wednesday, May 16, 2007

2008 Cadillac STS

Cadillacs need V-8s, at least. We know that. Except that GM's most potent V-6 ever, a new direct injection 3.6-liter, has come along. With its 11.3:1 compression ratio, it has 47 more horses than the 3.6 on which it is based. The '08 STS V-6 is just 18 horses shy and 22 pounds trimmer than the STS V-8. Keep the hood shut and no one will know.


Direct injection also gives slightly better fuel mileage and cleans start-up emissions by 25 percent. GM's plans for a new premium double-overhead cam V-8 thus becomes clearer. Direct gas injection, variable-valve timing and at least five liters displacement (to make sure it's sufficiently more powerful than this engine) is obviously in the works. The engine goes into production in 2009, in time for an all-new STS expected for the '10 model year.

Most direct injection gas engines start up with a gravelly diesel voice. Not the Cadillac's 3.6, with fuel system sound shields and covers to prevent metal-on-metal clatter. The engine remains quiet until you put your foot into it, unleashing a V-6 rumble satisfying enough to make you roll down the windows. It's wrapped in a facelifted STS with a Sixteen concept-inspired nose and a tastier interior that hides much, albeit not all, of the '07 STS' plastic-y parts with supple leather and vinyl as well as elegant woods and metals.

StabiliTrak 3 will be available for about $1,000, with a new active front steering system, offered at launch only with all-wheel-drive. This hyper-power steering feels more natural than BMW's, with none of the linearity problems. Cadillac's way of showing it off was to let us drive a conventional '07 and the new car with active steering around a handling course. The active steering required about half the left-right motion of the conventional steering, and we didn't have to remove our hands from 10 and 3 o'clock to make any of the turns.

There's also an effective blind-spot alert and lane-departure control, combined as a safety package for about $1,000. The blind-spot alert isn't alarming as in the large, vertical lamp in the base of the Audi Q7's side mirrors. Cadillac instead places an amber symbol in the side mirrors that light up when a vehicle enters a blind spot from behind. The lane-departure control beeps at you and lights up on the dash when you cross readable lane paint without signaling. You can drown out its beep if you crank up the tunes. Both warning devices can be shut off, but they're useful, and they'll reward the alert driver much more than the latte-drinking, mobile-phone wielding one.

Cadillac only let out the rear-drive '08 STS on public roads for initial impressions. Yes, the DI V-6 felt like a V-8, although its six-speed automatic hiccupped a few times, either a pre-production problem or lack of break-in miles. The interior still suffers hard black plastic, particularly at the top of the doors, but it's Cadillac's nicest non-v interior until the '08 CTS arrives. That car gets the same DI V-6 with slightly different power and torque numbers due to different intake and exhaust tuning. The kicker is that with its all-new interior and sheetmetal, the '08 CTS could render the STS V-6 as superfluous as an STS V-8.