The 2006 Audi S4 attempts to one-up the much-lauded BMW M3 by using the tried-and-true muscle-car practice of stuffing a larger car's V-8 under a smaller car's hood. The current M3 may squirt to 60mph a hair quicker than the S4, but the cachet, not to mention the sound, of the V-8 under its hood will probably make happy buyers out of some would-be M3 customers.
Under the hood, technology such as dual overhead camshafts, variable valve timing, and five valves per cylinder help the 2006 Audi S4's V-8 churn out 340 horsepower. With Audi's stalwart Quattro system driving all four wheels, the S4 remains composed and predictable, and electronic stability controls keep the power from overwhelming the tires on loose surfaces.
The face of the redesigned S4 features the signature Audi chrome-ringed grille, but the car is otherwise discreetly more masculine than the 2006 Audi A4 and pleasantly purposeful to behold. Sporting the bulging wheel arches of the new A4 but with rocker-panel cladding and a small rear spoiler, the S4 is different enough to be discernable but not showy. Our car's understated Light Silver Metallic paint ($475) fit the confident character of the styling; brighter colors will likely make the wide snout stand out more.
With an MSRP of around $46,000 and our car's as-tested price at $56,045, the 2006 Audi S4 is substantially dearer than the V-6-equipped A4, starting at about $36,000 for a Quattro. But the difference is both outwardly visible, if subtly so, and palpable from the behind the wheel. The S4's combination of performance, style, and AWD controllability is well worth the upgrade.