The 2009 Cadillac STS-V offers good handling and boast-worthy performance numbers, though it’s straight-line acceleration and on-the-edge performance isn’t quite in the same territory as other exclusive performance sedans.
The New York Times says the STS-V’s powertrain response wasn’t sporting enough: “The six-speed automatic transmission lags enough to be noticed, and even when all the horsepower is summoned, the STS-V prefers to stay true to its luxury-car roots.” However, most reviews echoed Edmunds’ sentiments: “Just dip the throttle and go. Mash the pedal and the STS-V jets forward on a huge wave of supercharged torque.”
Edmunds knows why the 2009 Cadillac STS-V is so fast: "the rear-drive STS-V is equipped with a supercharged 4.4-liter V8 engine that pumps out 469 hp and 439 pound-feet of torque." ConsumerGuide also loves the acceleration of the 2009 STS-V, noting that "Cadillac estimates 4.8 sec 0-60 mph, and it feels every bit that quick."
Automobile reports “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.” Edmunds notes that the automatic transmission on the 2009 Cadillac STS-V "has a tendency to move slowly through gearchanges." Cars.com was happy with the way the "supercharged Northstar engine teams with a six-speed automatic transmission" in the STS-V, calling the Caddy "an excellent example of a high-performance car that is more than livable in day-to-day driving."
The EPA estimates the STS-V's supercharged V-8 gets only 13 mpg city and 19 highway. ConsumerGuide tests indicate a rather dismal 13.7 mpg for the 2009 STS-V, for which premium gasoline is required.
Automobile nitpicks the STS-V's handling in comparison to German cars. “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.”
Cars.com says, “In our experience, the STS-V is an excellent example of a high-performance car that is more than livable in day-to-day driving.” Edmunds likes the car’s feel, though it finds it’s ultimately a softer sell than a certain German supersedan. “The car's rather large size ultimately limits its ability to hustle through corners, but it generally handles like a much smaller car,” they write. “Compared to the M5, the STS-V is softly sprung for American tastes, but body roll is well controlled, and the big Caddy never feels floppy or sloppy.”
Efficient stopping is just as important at quick acceleration and ConsumerGuide provides comforting feedback in this area, appreciating that "Reassuring brakes provide short, straight simulated panic stops."