Originally Posted by tileguy
i think you'll save more fuel keeping it at 60 or below.
from some research ive seen with trucks pulling trailers you can save .4 mpg driving at 58 mph vs 65 mph and a savings of 1.9 mpg from 70 mph to 58 mph.
i am sure it varies from rig to rig but you get the picture. speed is where you save fuel
Vehicles are still made to get the best mileage at 55-60 mph. This goes back to the 70's era when gas prices were relatively high and cars were bigger.
I have found that towing above 60, results in 1 3-4 mpg decrease in mileage on my truck, pulling my 30 foot toy hauler.