This is not your grandfather’s Cadillac. This is not your grandfather’s Cadillac. It’s the mantra quietly chanted by guys and gals at GM’s luxury division, though if you can’t believe it, fear not – a quick spin in the 2006 STS-V will hammer it home until your ears ring. That’s what a supercharged V8 does after the push-button starter brings it to life, stirring 469 horses and 439 lb.-ft. of torque, all sitting anxiously at idle as the melodic rumble of a powerful eight-cylinder engine thumps in the background.

Then you nail it.

Upwards of 435 lb.-ft. of torque is a glorious thing, and is necessary to move a 4,233-lb. mass to 60 mph in under five seconds. The 2006 Cadillac STS-V is indeed a very quick sedan, not only in terms of straight line performance, but also in the corners, where the independent suspension does a commendable job of controlling body roll and the Pirelli Euforia tires hold on tight, with just a bit of scrub on extremely aggressive turns. Despite its rear-wheel-drive platform, the STS-V exhibits a bit of understeer in the twisties. A competitive driving mode (CDM), as found on the 2006 Chevrolet Corvette, is selected by tapping the traction control button on the center console, and supposedly expands the limits of the StabiliTrak stability control system for livelier driving, though we were unable to discern any difference while traveling on public roads – if you get some track time with the STS-V, CDM might add an extra dose of excitement.

More appropriate for the street is the sport mode offered by the six-speed automatic transmission, a unit that provides seamless shifts under almost all circumstances, and is even smooth when the throttle is planted for sudden downshifts. Move the shifter to the right for sport mode, where the tranny will hold gears longer and keep the revs higher for better performance. There’s also a cool rev-matching feature that blips the throttle on downshifts, mimicking the heel-and-toe action of skilled race car drivers. For even more control, the knob can be tapped up or down for manual shifts, and the transmission will keep the engine knocking at the rev limiter rather than automatically shifting up a gear. Big Brembo brakes do an excellent job of bringing the Caddy to a quick stop, and seem to be impervious to fade even after steady abuse.

Though it’s engineered to be a capable performer, the 2006 Cadillac STS-V is also a comfortable luxury sedan. The power tilt and telescoping leather-wrapped steering wheel is great to hold, though like those in the Corvette and XLR, it’s too big. Front seats are spacious, and all outboard passengers enjoy padded armrests and door sills, while all five occupants can have their buns toasted. Around town and on mundane highway cruises, drivers will appreciate the quiet interior (though those induction silencers hardly eliminate supercharger whine at higher revs) and the compliant ride that’s a little stiff, yet offers a pleasant blend between sport and luxury.

Lest folks think the 2006 Cadillac STS-V the perfect car, there are a few negative points to consider. First is the lack of interior space, evidenced by the tight rear seat area with minimal leg room and no center headrest, and the narrow front foot wells necessitated by the wide powertrain tunnel. And the door and center console, though padded, are still tough on the knees in hard corners. Second is the steering, which could use a touch more road feel, and though it’s labeled speed-sensitive, needs more heft and feedback at higher speeds.