The Grand Cherokee EcoDiesel, the only diesel offering in the Jeep lineup, is powered by a 3.0-liter V-6 diesel engine that's different that the one powering the Ram 1500 EcoDiesel. The EPA has rated the vehicle at 28 mpg in highway driving. We tested the Summit 4x4 model, and were able to surpass that number. Read our driving impressions here. Photos by Kareem Girgis.