Cars.com reviewer Joe Wiesenfelder calls the 2010 Audi S4 a sleeper, noting that Audi has managed to add performance while achieving better fuel economy. The 2010 S4 knocks $4,400 off its sticker price by escaping the gas-guzzler tax. Yet Wiesenfelder still has one baffling question: Why does a T stand for supercharged?
