I recently bought a used 98 k3500 extended cab dually with a 350 vortec and the 4L80 transmission. I am getting about 11 miles to the gallon. It seems pretty consistent whether pulling, towing, or town driving. Is 11 miles to the gallon good or should it be a little better? After driving and exiting the vehicle I always smell gas fumes but have detected no leaks.
thank Danny