That's some impressive fuel economy! I'm forecasting 10mpg towing the same 6x12 U-haul from LA to DFW.10,180lb per truck scale. ~4500lb trailer with about 4000lb on the trailer axles and 6000 on the truck. It was heavy but drove a lot better than I thought it would. California to the Southeast. Averaged 14.9mpg with the 6 speed.