well I have a 36' Southwind with a 8.1 workhorse gas engine, and I pull a Saturn where ever we go. We have been to SD. AZ. and all the states between GA to SD. I have not had a problem with the gas engine pulling up the hills we went up or down. Now if you can do it as I do ,I change the oil, filter and lube it myself. That is one of the reason I bought the gasser. To do a diesel, be ready to get off the pocket book, IT COST and IT COST A LOT. But if I had the exyra bucks when I bought mine, well yes I would have gotten one. But since then I have found out the diesels needs to be on the road alot and as of now , I am not there yet. So we are happy with the gasser