Without Rocky on the back, my Tundra gets around 17 mpg. With Rocky it gets between 10-12, depending on how many mountain passes I have to go over.
This past trip was almost all interstate (I-25) with zero mountain passes and I got 12.6 mpg...the most ever towing Rocky! (The altitude at my house is 7,000 and the destination was at 4,900.)
Rick & Karen
(Retired USAF, MSgt)
5-year Travel Trailer RVers
2013 Forest River Rockwood Ultra-Lite 2904SS
2014 Toyota Tundra Maxcrew SR-5 TRD 4x4