The Audi S4 has a sonorous 340-horsepower 4.2-liter V-8 mated to a six-speed manual transmission and a lowered suspension. The already fabulous interior is dressed up with Recaro seats and aluminum trim. The S4 comes decently equipped for $48,070, but options like a Bose stereo and heated seats cost extra. Ours stickered at $51,620 and it didn't have a navigation system.
The S4 is exquisitely finished inside and out. The interior is stunning with its available two-tone seats and some of the best-quality materials and switchgear in any car at any price. The Audi is unique in this group with its Quattro all-wheel-drive system. This front-wheel-drive-biased system and a suspension set up with too much front-end stiffness conspire to produce understeer in nearly all situations. While the lack of the potential to rotate is surely confidence-inspiring for novice drivers, it hampers the fun quotient. The handling is further compromised by damping that isn't up to the aggressive spring rates; on bad surfaces, the car won't settle down and feels flummoxed. Don't let this lead you to think the S4 isn't fast around corners; it is. Just don't think you're going to throttle steer except at the absolute limit.
The S4's steering is nicely weighted but doesn't offer much insight into what the tires are doing. No matter; they're understeering. Trust us. The S4's brakes work fine on the road, but on the track they turned to mush while the other cars' remained firm and responsive. The S4 gets the job done capably, but it's not the dancing partner that the BMW and Cadillac are.
The S4 is a four-door sedan, but its back seat isn't much better than the two-door M3's, and it is far smaller than the CTS-V's. The S4 makes up for the lack of space with elegant surface treatments and styling. Put another way, being cramped isn't as much of a concern when leather, soft-touch plastic, aluminum, and Alcantara are doing the cramping.
If tail-out antics aren't your bag, the S4 might be. The Audi's shift action is well-weighted, and the clutch is far more user-friendly than the M3's on-off switch or the CTS-V's stiff affair. As a highway commuter, the Audi's somewhat softer ride makes it preferable to the other cars. Getting from A to B quickly is effortless in an S4; it is a supreme high-speed cruiser. But for it to offer the same level of driving involvement put forth by the other two cars in this test, everything needs to be screwed down another half turn.