This year has seen several new diesel passenger vehicles hit U.S. roads, and last fall, we were able to spend a full weekend with the 2013 Mercedes-Benz GLK 250 BlueTEC 4matic crossover.
We'd driven the luxury compact utility vehicle for a day last spring, and enjoyed it--but we wanted to put it through our usual drive cycle to see what kind of fuel economy it would return.
The diesel GLK, with standard all-wheel drive, is rated by the EPA at 28 mpg combined (24 mpg city, 33 mpg highway).
Over our usual test route, covering a total of 287 miles with about two-thirds highway travel and one-third local running around town, our diesel GLK delivered a stated fuel efficiency of 33.5 miles per gallon.
That compares with 33.1 mpg and 34.9 mpg during our spring day test.
Based on those results, we'd expect real-world figures to come in at a consistent 30 mpg--perhaps higher--showing once again that many diesel cars exceed their EPA fuel-economy ratings.
That 30-plus-mpg figure is about half-again as efficient as a gasoline GLK 350 model, which is powered by a 3.5-liter V-6 engine and rated at 21 mpg combined--with either rear-wheel drive or 4Matic all-wheel drive. It recommends premium gasoline, to boot.
The Mercedes-Benz GLK is a very quiet vehicle at speed, and we found it extremely comfortable as a long-distance highway cruiser. The same applied to a full-size diesel Mercedes-Benz S 350 BlueTEC sedan we tested in the summer of 2012.
But we noticed some turbo lag when driving the GLK in stop-and-go traffic; not as much as in the Chevy Cruze Diesel, but more than in the 35-mpg Audi Q5 TDI we recently tested.
We noticed some aggressive engine braking on a downhill stretch of our road before the GLK had warmed up. We also found the brakes to be a little grabby--although with 6,500 miles of press usage, that may not be attributable to the car but to its previous drivers.
2013 Mercedes-Benz GLK 250 BlueTEC 4matic, Catskill Mountains, NY, Sep 2013Enlarge Photo
The GLK was launched as a 2010 model, and the upright, square-cut styling modeled on the huge GL three-row utility vehicle is beginning to show its age. The windshield is remarkably upright for a 2014 model, though rear three-quarter visibility isn't particularly good despite the upright roof pillars.
So are the flat surfaces and angular lines of the interior--and for that matter, the genuine built-in ashtray and cigarette lighter as well, the first ones we've had in a test car in a couple of years.
But we found its cream and cocoa upholstery and trim tones especially luxurious, set off by flat silver trim, against the more typical all-black German interior.
Quirks and oddities
None of the GLK's design is bad, it's just no longer consistent with the more aerodynamic and flowing lines of recent Mercedes-Benz models, especially the new CLA compact sedan and the upcoming GLA small crossover.