Sports Car Comparison: 2004 Audi S4 v

Sedans are good. Sport sedans are better. Performance sedans are great: those stealthy four-door "saloons" that easily blend into the commuter landscape yet have the performance capabilities of sports cars.

The '04 Audi S4 and the '03 Mercedes-Benz C32 AMG are at the top of this rare class and are leading the way into a high-performance realm where one would expect to see names like Chevrolet Corvette or Porsche 911. Judging by the ink-on-paper potential and the actual track results these two compact four-doors produce, you'd think the Germans have an affinity for hiding big horsepower in small, inconspicuous places--and that they get a strange thrill out of shocking unsuspecting passengers and fellow motorists. Correct on both counts, so consider yourself warned.

The 340 horsepower produced by Audi's 4.2-liter V-8 and the 349 from the AMG-supercharged 3.2-liter Mercedes-Benz V-6 both surpass the BMW M3's 3.2-liter/ 333-horsepower I-6 rating. Who needs a small car with that much power? Truly, nobody, but that was exactly the impetus for the now-legendary '64 Pontiac Tempest GTO--and we know where that led.

So why wasn't a BMW M3 included in this comparison? Its credentials and pricetag indicate it's certainly in the same league. Simple: This roundup is for four-doors, and the M3 is not currently offered as such. As a stopgap until that happens, BMW has introduced a $3900 "Performance Package" option for the 330i sedan, which somewhat approximates an M3 sedan--but, unfortunately, without the high-winding, 333-horsepower M-spec straight-six.

That the Audi and the Mercedes-Benz are both fast German cars painted silver is about all they have in common. The Ingolstadter drives all four wheels, while the Affalterbacher prefers rear drive. Strangely, they've seemingly switched camps when it comes to preferred engine architecture: force-fed V-6 or single-atmosphere V-8.

Audi's previous S4 (2000-'02) used a twin-turbo 2.7-liter/250-horsepower V-6. The new S4 has a naturally aspirated V-8. On the other side of the fence, from '98 to 2000, Mercedes shoehorned a 4.3-liter/ 302-horsepower V-8 into its C43, but the company now chooses a supercharged V-6 for the C32 AMG.

Which is better? That depends on how you intend to drive and how you define "rewarding."