Never gotten better than 13.5 HWY and that's with a feather foot doing about 65MPH. Usually get about 12.6 moving at 75 or so.

Pretty much around 10.5 to 11.5 around town.

Both went up by 1.5MPG when I ditched the 35 X 12.5 tires and went to 295 75's. Rides better too.