My 2012 VW Touareg TDI gets about 14.5 mpg towing a 4,500 lb TT. It's essentially the same option as the Jeep Grand Cherokee. Unfortunately you can't buy one new right now due to dieselgate, but maybe after June 21st. You can find them used.
Touareg reliability is excellent. No problems with 103K miles and counting. Best vehicle we ever owned and plan to drive it into the ground. We have an Escape trailer on order we plan to tow with it. If I can't get another TDI Touareg after this one is done I'll probably go over to Jeep, but I am scared about reliability as others have mentioned. Lots of stories out there.