ML350 Bluetec mileage
Without the trailer we average 30 mpg on highway, mid 20s in town. Last trip with the trailer we were getting 18 mpg at 65-70 mph for a 220 mile trip to Maine.
We got the ML350 mainly for that reason, ie good mileage with a great towing capability in a non-truck package that also looks pretty smart.
Wish American manufacturers would produce something similar, only vehicles we found that meet the specs (good mileage, good towing capability, not a truck) were all German (Mercedes, BMW, Audi, VW).