I tow a 16' Casita SD with a 2010 Flex with the turbocharged engine. I've towed only once on a 6 hour ride. My recollection is that I saw 12-14 mpg. I thought it towed great. I use a WDH. Tow rating for the vehicle is 4500 pounds and the trailer runs about 3000 (its been weighed) in my travel trim.