Engineers put a lot of effort into making the 2006 Cadillac STS-V worthy of its V-series designation, though at the heart of it all is a superb supercharged engine. The 4.4-liter, 32-valve, dual overhead cam, Northstar V8 with variable valve timing cranks out 469 horsepower at 6,400 rpm and 439 lb.-ft. of torque at 3,900 rpm, with peak twist available between 2,500 and 6,400 rpm. This aluminum powerplant is the same used in the XLR-V roadster, but because of necessary tweaks in that car’s exhaust manifold and oil pan, the STS-V ends up with an extra 26 horses and 25 lb.-ft. of torque Based on the popular 4.6-liter V8 currently used throughout much of the Cadillac lineup, the 4.4-liter motor incorporates the use of new heads, crankshaft, pistons, and connecting rods, a multi-layer steel head gasket, twin induction silencers designed to limit supercharger whine, and a Roots type supercharger offering 10-12 psi. Each engine is hand-built in Michigan, and ultimately connects to a six-speed, manually-interactive automatic transmission. When it’s all bolted in place, the stout powertrain catapults the 4,233-lb. 2006 Cadillac STS-V to 60 mph in 4.8 seconds, with a top speed governor-limited to 155 mph.

Impressive as it may be, straight-line performance is only one of the STS-V’s strengths. Handling is also enhanced with a sport-tuned independent short- and long-arm front suspension and an independent multi-link setup in the rear; front and rear stabilizer bars are standard, as are traction control and StabiliTrak stability control systems and a limited slip differential. Speed-sensitive steering, with a quicker response than offered in the regular STS, further aids overall control. Collectively, this package has led to a 15-percent increase in ride stiffness, a 35-percent increase in roll stiffness, and a 17-percent decrease in understeer. According to Cadillac, the 2006 STS-V pulls 0.87g on the skid pad, which, not so coincidentally, is the same figure reported for the 2006 BMW M5.

Charged with halting all of that forward momentum is a beefy antilock disc braking system with electronic brake assistance. Those Brembo components sit behind alloy wheels rolling on 255/45R18 Pirelli Euforia tires up front and 275/40R19s out back. These are run-flats supposedly good for 50 miles of travel after being damaged.