WHO NEEDS A HYBRID? Audi launches pair of new TDI-powered A4 models; sedan to get 53.5 mpg. “Packing 2.0-liter TDI engines, the pair of new models – a sedan and an Avant (wagon) – boast near best-in-class fuel economy ratings of 53.5 mpg (U.S.) and 51.1 mpg, respectively. . . . Increased efficiency often comes at the expense of performance, but Audi claims that its 2.0-liter TDI mill makes no such sacrifice. Engine output is listed at 136 horsepower and torque at 236 pound-feet which combine to propel the A4 sedan to 62 miles per hour in 9.5 seconds and on to a top speed of 134 mph. The wagon, with its added weight, completes the sprint to 62 mph in 9.8 seconds and continues to 129 mph before packing it in. Both models feature a six-speed manual trans with slightly lengthened gear ratios, some aerodynamic tweaks aimed at improving drag and come shod with low-rolling resistance tires.”