I have a 54/235 with fenton headers and offy intake with 2.73 and a t-5trans also 235/75/15 tires. in town i get 12-13 mpg. on the road in 5th gear i average 20 mpg, and i have seen a high of 23 mpg driving at 70 with the cruise on. these are documented and calibrated speeds. i got 17 going over the mountains in WV in April.
