Audi and Mercedes-Benz both began offering diesel-powered compact crossovers in the U.S. The U.S. isn鈥檛 historically a market prone to diesel purchases, but that鈥檚 slowly starting to change. What used to be an unusual fuel reserved for heavy-duty trucks is trickling into high-end luxury showrooms. Take the Audi Q5 and Mercedes-Benz GLK 250 BlueTEC as examples. They both offer torque-rich turbo diesels in a small package. Both boast relatively conservative fuel consumption without the sort of power sacrifices you might expect. Rosy as that might sound, there are drawbacks. As a fuel, diesel tends to be more expensive per gallon. It鈥檚 also harder to find because fewer gas stations sell it than, well鈥?gasoline. Audi slaps its familiar 3.0-liter turbo diesel V6 into the Q5 - the same unit used in the A6, A7 and A8 - while Mercedes makes do with a 2.1-liter turbo four. They compete in the same class and use the same fuel but offer a different end product. With that in mind, we decided to drive them side-by-side to determine which of the two brands offers the better solution to selling a product in such a niche segment.

Audi and Mercedes-Benz both began offering diesel-powered compact crossovers in the U.S. The U.S. isn鈥檛 historically a market prone to diesel purchases, but that鈥檚 slowly starting to change. What used to be an unusual fuel reserved for heavy-duty trucks is trickling into high-end luxury showrooms. Take the Audi Q5 and Mercedes-Benz GLK 250 BlueTEC as examples. They both offer torque-rich turbo diesels in a small package. Both boast relatively conservative fuel consumption without the sort of power sacrifices you might expect. Rosy as that might sound, there are drawbacks. As a fuel, diesel tends to be more expensive per gallon. It鈥檚 also harder to find because fewer gas stations sell it than, well鈥?gasoline. Audi slaps its familiar 3.0-liter turbo diesel V6 into the Q5 - the same unit used in the A6, A7 and A8 - while Mercedes makes do with a 2.1-liter turbo four. They compete in the same class and use the same fuel but offer a different end product. With that in mind, we decided to drive them side-by-side to determine which of the two brands offers the better solution to selling a product in such a niche segment.

Get the Flash Player to see this player. To be clear, the segment they share and the fact that they both use diesel engines are really the only fundamental attributes the Q5 TDI and GLK250 BlueTEC share. 10,000 more than that. The Q5 has more torque, horsepower, gears and is more expensive. The 3.0-liter turbo diesel V6 makes 240 hp and 428 lb-ft of torque that also drives all four wheels, but through an eight-speed automatic. As with their powertrains, Audi and Mercedes-Benz have vastly different ideas about what makes a stylish car. Ingolstadt鈥檚 finest favor smooth lines and a conservative style that characterizes its vehicles with instantly recognizable uniformity. Standard exterior equipment includes 19-inch alloy wheels and 14 paint color choices, two of which are free (black and white). Stuttgart-based Mercedes-Benz traditionally tends toward more angularly styled cars. That鈥檚 starting to change, but the GLK is still a stronghold for hard edges. If you squint hard enough behind a pair of rose-colored glasses, it almost looks like a G Wagen.

1,990. It includes 19-inch five-spoke AMG wheels, AMG body styling and aluminum roof rails. Also, Mercedes offers not two, but three no cost paint colors: black white and red. 1,515 for metallic 鈥渄iamond white.鈥?As with the Audi, extras as totally unnecessary here. The based GLK is handsome enough on its own. Stark styling differences continue inside. The Q5 is chock-full of black soft touch surfaces accented with a selection of wood trims or aluminum. Its seats cradle you with bolstering on the sides that leaves the GLK鈥檚 front buckets feeling flat. From behind the wheel, you have access to customizable drive modes, Audi鈥檚 MMI infotainment system and a gas pedal that governs the boosted V6鈥檚 powerful acceleration. But more on that later. The Q5 also has slightly more rear seat legroom than the GLK and better cargo capacity with 29.1 cubic feet compared to beat the Benz with almost 20 percent more space behind the second row. But does all that really matter? Truthfully, no. The GLK is more than adequate with 23.3 cubic feet to keep your things and that space is more practical because of the boxier body.

That shape also means GLK buyers get more rear seat headroom. Remember, you can always adjust the front seats a little bit but the ceiling is fixed. Even at the higher trim levels, Mercedes will charge you for leather seats and that鈥檚 frustrating. There are more hard plastic surfaces here than in the Audi and plunger-style door locks leave the car feeling cheaper by comparison. Keep in mind, that鈥檚 because it is quite a bit cheaper than the Q5. The two cars sit in sort of a tied ball game with their infotainment systems. They鈥檙e both straightforward to use and after a day with either, you鈥檒l be completely comfortable. Audi鈥檚 3.0-liter TDI engine makes the Q5 fast. The company says it reaches 60 mph in 6.5 seconds but with 428 lb-ft of torque at your right foot it feels quite a bit faster. There鈥檚 a little bit of turbo lag but after that you鈥檙e sitting in a rocket ship. The eight-speed delivers smooth, responsive gear changes and aside from the early shift points it鈥檚 almost hard to know you鈥檙e driving a diesel. 3,500 you can add Audi鈥檚 S line package.