Audi Q7 Diesel, a 5,500-Pound Fuel Miser

The Audi Q7 3.0 TDI is an SUV to consider if your needs call for a three-row SUV and you want the best possible fuel economy and range for that kind of vehicle. Drive gently and this 5,500-pound Audi will reward you with almost 30 mpg. The EPA rates it at 17 mpg city, 25 mpg highway, 20 mpg combined. I got 27 mpg in a long weekend of driving, mostly highway miles. With its massive 26.4 gallon fuel tank, you'll go 600 miles between fill-ups. Highway cruising is where a diesel-engine vehicle is most at home.

The all-wheel-drive Audi Q7 doesn't have quite the bulky feel of a Cadillac Escalade. But the tall silhouette and massive Audi-signature grille, big enough to keep salmon from being sucked into a nuclear plant water intake, are a fair indicator of the official specs: 200.3 inches long and a weight of 2.75 tons. The 225-hp diesel is the slowest of the three Audi Q7s, although 0-60 mph in 8.5 seconds is still pretty good. As with most other diesel-engine cars and SUVs I've driven this year, it's virtually impossible to tell it's a diesel from the inside, except when starting up and driving away on cool mornings. From the outside you hear a slight clatter at idle and, if you sniff hard, you'd notice the slightest bit of diesel odor. As with many other low-emissions diesels, the Q7 injects urea into the exhaust stream to further purify the emissions. The tank is good for 7,500-10,000 miles, so it can be handled when you go in for an oil change.

Audi has plenty of technology features and options. An iPod adapter comes standard. Audi's MMI (multimedia interface) cockpit controller was for the longest time the smarter, easier-to-use alternative to BMW iDrive; the current iDrive has since leapfrogged Audi. (Expect a significant Audi enhancement in 2010.) If you order navigation ($2,500, a lot to pay), you'll see 3D topography with building shapes in some areas thanks to an nVidia processor, get real time traffic, and a 40-GB hard disk that reserves 10 GB for ripped CD music. A blind spot departure warning system is offered but not lane departure warning. The daytime running lights are LEDs, as are the taillights. There's no rear seat entertainment package offered, but you can add one easily through a mobile entertainment dealer.