Are large gas motor Rv's underpower?

John S. wrote:
I would say the issue is not underpowered but longevity. I just turned 163k on my coach. I am not concerned about the drivetrain. If I had a gasser, I am sure I would be thinking of a new engine or transmission sooner or later. Now some people put a few miles on but the old diesels of the early 90s are still running strong on the original drivetrain. If you are going to travel 5k a yr and keep it under 10 years either works but mine is now 13 years old and I totally remodeled the inside and it is good for another 13 years at least. Friends took a 93 up to Alaska this summer. The other thing people forget when they say floor plan is the deciding factor is how you are going to use it. I have 110 gallons of water and a 110 grey and 80 black tank. I can boondock pretty easy and for a while and my fuel rank is 200 gallons too. Means I can drive across country filling up at the cheapest locations.

It is all relative. If I were you, at the age and mileage on your coach, I would be worried about the radiator going bad, which from reading the numerous posts on this forum about DP radiator problems, can easily cost as much as a rebuilt long block for a gasser.
I also agree that you probably have a longer range but figuring that you pay 50 cents or more a gallon($100/fill-up) the extra fuel cost for your 200 gallon tank, that is not really all that good.
Using your 163,000 miles, at 8 MPG, you spent an extra $10,000 for your fuel then the same gas engine would have spent. That is more than enough for a new gas engine, even tho both the Ford and GM engines were designed for 250,000 miles. There is no doubt that some DP's are superior to some gas powered coaches but the question was whether the gas RV was underpowered, which as many gas owners have stated, they are not.