07-13-2019, 05:44 PM
My average over about 40,000 miles with a CAT C15 with Allison towing about 6,000 lbs was 5.6 mpg. As others have indicated you can get better mileage on the flats or going downhill but everything combined I was getting only 5.6 mpg and that is driving between 65-70 mph most of the time. I was going back and forth over the rockies quite often too.
Oscar & Janet Valent
Full timing
2004 Foretravel U320 3820 PBBS
2007 Newell Coach #815 - Great Coach Sold
2015 Jeep Grand Cherokee Summit