2014 Audi Q5 TDI vs 2014 Mercedes GLK 250 Bluetec

Power vs. Efficiency: Two Takes on the Diesel Luxury Crossover

Audi and Mercedes-Benz both began offering diesel-powered compact crossovers in the U.S. last year. The U.S. isn’t historically a market prone to diesel purchases, but that’s 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’s also harder to find because fewer gas stations sell it than, well… 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.

A Brief Breakdown


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2014 Audi q5 tdi grilleTo 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. The Mercedes offers considerably less horsepower and torque with 200 hp and 369 lb-ft directed to all four wheels via a seven-speed automatic for a starting price of $38,980. Our tester cost roughly $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. Pricing starts at $46,500 but our test car cost almost $60,000.

Style Served German

2014 Audi q5 tdi vs glk 250 grilles

As with their powertrains, Audi and Mercedes-Benz have vastly different ideas about what makes a stylish car. Ingolstadt’s 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).  If you prefer, Audi will sell you 20-inch wheels for another $800.

2014 Mercedes GLK 250 front profileStuttgart-based Mercedes-Benz traditionally tends toward more angularly styled cars. That’s 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. Almost. That becomes more the case if you add the “sport” package for $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. Alternative hues add $720 to the bottom line unless you’re willing to spend $1,515 for metallic “diamond white.” As with the Audi, extras as totally unnecessary here. The based GLK is handsome enough on its own.

Cabin Fever

2014 Audi Q5 TDI Interior seats

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’s front buckets feeling flat.

From behind the wheel, you have access to customizable drive modes, Audi’s MMI infotainment system and a gas pedal that governs the boosted V6’s 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?

2014 Mercedes GLK 250 Interior Steering wheelTruthfully, 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’s 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’s 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’re both straightforward to use and after a day with either, you’ll be completely comfortable.

Driving It Home

2014 Audi q5 tdi 3

Audi’s 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’s a little bit of turbo lag but after that you’re sitting in a rocket ship. The eight-speed delivers smooth, responsive gear changes and aside from the early shift points it’s almost hard to know you’re driving a diesel.

For $3,500 you can add Audi’s S line package. It adds 20-inch “titanium finish” wheels and sportier accents that include a flat-bottomed steering wheel, brushed aluminum inlays, paddle shifters and an adaptive damping suspension. Combined with the burly powertrain, the package makes for impressive handling capability.

Careful sound deadening keeps the clattering powerplant out of earshot unless you roll the window down. Then it’s pretty noisy.

Compare Specs

2014 Mercedes-Benz GLK250 BlueTEC
2014 Audi Q5 TDI
Vehicle 2014 Mercedes-Benz GLK250 BlueTEC Advantage 2014 Audi Q5 TDI
Engine 2.1L turbo diesel I4 - 3.0L V6 turbo diesel
Horsepower 200 Q5 TDI 240
Torque 369 lb-ft Q5 TDI 428
Fuel Economy (EPA) 24/33/28 GLK250 24/31/26
MSRP $38,980 GLK250 $46,500
As tested $48,540 GLK250 $59,800
Cargo Capacity (seats up) 23.3 Q5 TDI 29.1
Rear Head Room 39.7 inches GLK250 39 inches
Rear Leg Room 35.1 inches Q5 TDI 37.4 inches

It’s the same story with the GLK, albeit engine noise is even less noticeable, perhaps because of its smaller displacement. That also means less output but don’t dismiss it on those grounds. You probably won’t miss the Q5’s power with 369 lb-ft of torque and a pair of sequential turbochargers. The GLK is also 154 lbs lighter on its feet and that probably makes a little bit of a difference.

2014 Mercedes GLK 250 wheelIt’s still nowhere near as athletic to drive. You can feel it leaning through corners and with fewer customizable drive settings, you won’t be spending time creating personalized modes. Does that really matter?

There might be no greater non sequitur to the compact crossover segment than performance. Practicality matters and if you’re buying something with a diesel, it’s probably for the fuel economy benefits. The thing is, the GLK is much more practical, even when it comes to driving.

The boxy shape gives you better outward visibility and makes it easier to park. Both cars are efficient on paper but the GLK is much better in real world daily driving and that probably has something to do with its milder road manners.

The Verdict

2014 Audi q5 tdi vs glk 250 3

The Audi Q5 TDI is faster, sportier and has more cargo space. It’s also much more expensive and in the end, that drags it down. Mercedes’ GLK 250 BlueTEC might not be the hotter choice but it’s by far the more practical. If you’re pondering a premium diesel purchase in this segment, it’s the one to get.