rv gas mileage

I have had both a gasser and a Diesel. My Gassers were Itascas with the Ford V10. The last one was a 2008 Sunova, we towed a Jeep Liberty about half the time, over 8 years of ownership and about 40,000 miles we averaged 6.5 mpg. We recorded every fill. We now own a 2016 Tiffin RED with a 360Hp Cummins and an Allison 3000. We are getting around 8.5 but have gotten more. Still too new to tell for sure. Short trips seem to get lower mileage, too high a percentage of the trip is the approach and landing at both ends. Longer trips get better mileage as the Hills and the town and back road portions are less of a percentage. You will likely get better mileage with a diesel, it will cost you more, but you also get more in the rig itself. Going up hill we are not challenged unless we get stuck behind someone and can't get around early enough, then we can wind up in the lower gears with the flashers on, just like the trucks. Here is the good news. we have double the towing capacity we had and we have more cargo carrying capacity than we can use with the Diesel. The gasser was MUCH noisier and that was even worse on a hill.

I would be seriously skeptical of any claims of double digit mileage from any large MH, Yes, my brother has a Class B and gets 16-17, of course we could literally fit two of them inside my Class A! So make sure you compare apples and apples, Weight and frontal area are MAJOR contributing factors to mpg.