The GL350 Bluetec may not be the leader in power, torque, or fuel economy, but Mercedes has done a fabulous job integrating the diesel powertrain. From the cabin, the engine is as smooth and quiet as a refined gasoline powerplant, and the seven-speed automatic makes light work of masking shifts. I'll concede that the Mercedes isn't my top choice of the three German SUVs, but it's still a great truck.
Fuel economy has always been the reason to purchase a diesel, but improvements in drivability and a broader selection will hopefully spur interest and sales. Compared with the gas-burning GL450, the Bluetec diesel yields an improvement of 4 mpg in the city and 5 mpg on the highway. Over 12,000 miles of mixed driving, that results in about 180 gallons of fuel saved -- a significant savings with no sacrifice in comfort or capability.
Eric Tingwall, Associate Editor