With its all-new A4, Audi has pulled off a rare hat trick -- producing a car that's bigger, faster,andmore fuel efficient. Audi's powertrain brains developed the valvelift system in order to allow for ...

Ever since we picked up the Audi A4 for our long-term test, this is the comparison I’ve been itching to do. It’s the obvious choice to see how far the A4 has come in this generation, and whether it ...