Generally speaking as I have owned both a Gasser and diesel. The maintenance cost for a diesel pusher will be at least double of that of a Gasser if taken into say five-year maintenance history. Both are about to need tires Gasser 2000 diesel 3500. At the average of 10,000 miles a year the Gasser will need two oil changes at under hundred dollars each and the diesel will need one at $300 plus at the same time the diesel will need two fuel filters only about $80 this is per year. The Gasser will need two or three air filters over the five-year period the diesel will need at least two the Gasser's $20 each the diesels upwards of $200 each. On the diesel you'll need air/dryer filter for the air brake system once maybe twice at $180 per kit with a Gasser at a little brake fluid. Somewhere in that five years or nearing it you'll need new start batteries for both rigs the diesels usually run two the Gasser's run one. The transmission service will be at least twice as much on the diesel.Gas mileage is kind of a wash both get between 6 and on the outside edge 10 miles a gallon so the fuel mileage is near the same. With the new Gasser's coming out with upgraded interiors the approaching what might be a diesel standard but the ride is not near as good. As far as power definitely the diesel has more and is going to pull better. But in my opinion because of fluid levels maintenance levels the diesels going to be per year about twice as expensive especially if you don't do the oil changes and other maintenance yourself.
LEN