Push the starter button to the right of the Cadillac STS
-V's steering wheel, and the supercharged V-8 leaps to life while the driver-information LED display briefly illuminates the greeting, "Ready for STS-V?" After spending a week with the most powerful Cadillac
ever produced, we'd like to throw that question back at Cadillac, and at GM: Are you ready for STS-V? Is Cadillac, which has been scratching and clawing its way back to respectability, really prepared to go head-to-head with AMG-tuned Mercedes-Benzes and M-badged BMWs? Or is the STS-V, like the CTS-V, a noble, competent, and entertaining effort that ultimately is compromised by unattended details?
If it is, it's certainly not for a lack of V-series enthusiasm among GM engineers, who giddily describe the modifications they've made to the base STS to arrive at the STS-V. The most important of these changes, of course, is the new, supercharged, 4.4-liter version of the Northstar V-8, which produces 469 hp and 439 lb-ft of torque, increases of 149 hp and 124 lb-ft over the normally aspirated 4.6-liter V-8.
Development of Cadillac's first supercharged production engine extended beyond simply nestling the Roots-type blower between the V-8's 90-degree cylinder banks. To fortify the Northstar for this assignment, the cylinder bores were reduced from 93 to 91 millimeters, which resulted in the smaller displacement, and the engine block is sand-cast rather than die-cast, for a 40 percent improvement in fatigue strength. New cylinder heads, heavy-duty pistons, revised connecting rods, and a lower compression ratio-9.1:1 versus 10.5:1-also help accommodate the additional output. The supercharger itself is a particularly well-packaged and well-engineered piece, with long, high-twist rotors generating the added air flow plus trick water-to-air tubular intercoolers with fins that look like the underside of a portabella mushroom. "The Northstar's four-cam variable valve timing allows us to exploit the blower's output," says engineer Greg Prior. "We're really exercising the cams."
Exercise your right foot, and the blower responds with a progressive buildup of power and rotor whine that's less intrusive than that of the supercharged Jaguar V-8. The Northstar, though, does not produce the locomotive-like thrust of the Mercedes E55 AMG's mighty 5.4-liter supercharged V-8. "We match the E55 in power," Prior boasts, "with one liter less displacement." True, but the Northstar is down 77 lb-ft of torque on the AMG V-8, and it's the E55's seemingly endless supply of torque, the accelerative forces that bury you into your seat as if you're in a Gulfstream V on takeoff, that make the Mercedes worth its premium over the Caddy.
Not that the STS-V is anything like slow. In our tests, it clocked the 0-to-60-mph run in 5.3 seconds and the quarter-mile in 13.9 seconds at 105 mph, as compared with 7.0 seconds and 15.3 seconds at 95 mph, respectively, for the stock STS V-8. (The last time we tested the E55, in December 2002, we saw a 5.0-second 0-to-60-mph time and ran the quarter-mile in 13.1 seconds at 112 mph.) You will not want for power in the STS-V, but the all-new six-speed manu-matic transmission doesn't always transfer the engine's goods to the rear axle as smoothly as you would expect, whether it's in fully automatic mode, on the sport setting, or in manual-shift mode, when it has an especially difficult time with the two-three upshift.
Directing its attention to the STS chassis, the V team kept the same basic suspension setup but ditched the MagneRide electronic damping, as they wanted a "more narrow range of control." They also specified higher spring rates, larger-diameter antiroll bars, a meaty engine-compartment brace, and Pirelli Euforia performance run-flats-255/45YR-18 front, 275/40YR-19 rear-footwear we found a bit harsh over rough pavement. The Brembo brakes that migrate from the CTS-V, with 14.0-inch front and 14.3-inch rear discs clamped by four-piston calipers, resisted fade even during repeated hot laps of GM's challenging new Milford Road Course, but we'd like a more positive-feeling brake pedal.
The STS-V storms around Milford quite happily for a 4343-pound sedan, but it doesn't feel like all of its mechanical systems are in harmony. It's missing the fluidity that eludes so many GM products but which is usually present in the best performance cars from, you guessed it, Europe. And the Caddy's steering is too quick off-center and simply doesn't light up the lines of communication between the road and the driver.
Aesthetically, the maximum Caddy sedan suffers from its genesis as the anodyne STS, a car whose exterior and interior both leave us cold. The STS-V's stainless-steel mesh grille and lower air intake, ten-spoke aluminum wheels, fatter-lipped front fascia, and rocker extensions go a long way toward giving this car some real visual appeal, though.
The V team enlisted the help of Mercedes-Benz's cabin supplier, Drxlmaier, to outfit the STS-V with French-stitched, beautifully grained leathers for the top of the dash, the center console, and the door panels, but these exquisitely realized pieces stand in stark relief to the rest of the cabin, which is decidedly lower rent. It doesn't help that the basic design of the STS instrument panel is inoffensive but utterly uninspired, nor that the STS-V's seats are essentially carried over from the STS, save their ultrasuede inserts. If only the STS-V had more richly crafted instruments, and if only its seat upholstery also had been farmed out to Drxlmaier, this cabin might begin to measure up to the Audi A8's or the Maserati Quattroporte's.
If only. If only we'd stop comparing the STS-V with the Europeans, you might be thinking, we'd realize that it's a pretty darn good car. But Cadillac itself identifies the BMW M5 and the E55 AMG as its bogeys, and it has priced the $77,090 STS-V accordingly. But the STS-V is more of a classic American hot rod, with all manner of performance goodies bolted onto a car that's only midpack in its field, than a pedigreed performance sedan. Chrysler's SRT8 version of the 300C is essentially the same concept-except the 300 is actually a standout in its own field-yet it's about half the price of the STS-V. Cadillac has made huge strides, but this car just can't compete with Europe's best. Cadillac may be ready for the STS-V, but the STS-V is not quite ready for prime time.
Engine: Supercharged 4.4L V-8, 469 hp, 439 lb-ft