For its first three model years, the Mercedes GLK hasn't done very well in the gas-mileage derby. While other luxury crossovers have nudged 27 miles per gallon on the EPA highway cycle, the 2010-2012 GLK topped out at 16/23 mpg for the rear-wheel-drive model.
We expect that to change in the 2013 model year, for two reasons--those reasons being a new V-6, and a new turbodiesel four. The V-6 offers direct injection and stop/start technology, while it keeps the seven-speed automatic and the option of rear- or all-wheel drive. Official numbers haven't been released yet but we expect a healthy increase in fuel economy. We'll update this rating and this page as soon as those figures are available.
The other option is why we've nudged the GLK's rating a full two points above last year's score. With a new turbodiesel 2.1-liter four, the GLK could end up sporting the best fuel-economy ratings in the class, by a healthy margin. Since it doesn't go on sale until early 2013, the diesel's EPA figures are still under wraps, but a 30-mpg highway rating isn't out of the question. We'll also revisit this page to update the diesel numbers when they're released.