While Japanese automakers have the hybrid lead, the front-runners in diesel are companies of German descent. Mercedes is bringing home the bacon with BLUETEC, BMW is slapping twin turbochargers onto a 3.0-liter diesel, and Volkswagen will implement BlueMotion into five different VWs. Audi intends to join the oil-burning club here in the States with the introduction of the 3.0 TDI, which is good for 240 HP and 406 lb.-ft. of torque. With all that twist, tires should scream from rubber-stripping takeoffs, but even aggressive driving won't translate at the pump as bad as their gasoline counterparts. Audi expects a 35-percent fuel economy bump vs. similar gasoline powerplants.