The 2010 Audi S4 drops the 4.2-liter V8 for a 3.0 supercharged V6 with less power and a strange "T" badge. Is that the recipe for a sport sedan finally capable of besting arch-rival BMW and making our 2010 Best10?

That "old" 4.2-liter V8 produced 340 HP and is still used in nearly every car Audi makes, from the platform-sharing 2010 Audi S5 to the Audi R8 4.2. It's an amazing engine in all its forms, combining V8 sound with instantaneous revs. Hopping in the S4 for the first time, I was pretty disappointed by its absence, the new direct-injected and supercharged V6's drone would sound right at home in a Camry and there's no audible sign of the supercharger whatsoever.

But that humdrum new sound and the "V6T" badges are masking what's actually an exceptional engine. Power is down 7 HP to 333, but torque is up by 23 Lb-Ft to 325, with the peak now arriving 900 RPM earlier and spreading across a plateau from 2,900 to 5,300 RPM. The effect of that is predictably much more low down shove for everyday driving, but, unpredictably, fuel economy gets a huge boost from 13/20 (city/highway) on the V8 to 18/27 MPG for this manual six speed.

The new S4 is also cheaper, with the base version starting at just $45,900, $2,710 cheaper than the old V8 and without the $1,700 gas guzzler tax on top of that price tag.

But that's only the beginning. The 2010 S4 also comes with an optional $1,100 torque-vectoring rear differential that works with the 40:60 front to rear power split and stability control to all but completely eliminate understeer. An Audi without understeer? This is starting to get interesting.