Luxury cars have seldom been known for their high fuel economy, and SUVs have also never been known for being frugal with gas. Put the two together and you have a recipe for fuel consumption that would make an oil executive put a down payment on a second yacht. Bucking this trend, though, is the 2011 Audi Q5. Notable this year for the Q5 is a new turbocharged four-cylinder engine that delivers only a couple mpg less on the EPA driving cycles than the Audi A4 Avant wagon. Even the Q5 with its available, more powerful V6 is pretty good on gas. Yet fuel economy is only one of the Q5's many virtues. Thanks to its underpinnings from the Audi A4 sedan, the Q5 is one of the most entertaining vehicles to drive in the segment of luxury crossovers. It has the confident handling and alert responses of the A4, yet the Q5's decent cargo hold and generous passenger space mean it's pretty comfortable and practical, too. Indeed