I got an email today asking me which I would recommend for a motorhome chassis: a gas or a diesel. With so many variables it hard to give a correct answer. It depends on how you drive, how often you drive/how many yearly RV mile will you put on and finally, the known reliability and lifespan of any chassis/engine/drivetrain you consider.
So, here is my blanket answer to you, @RVLifeOnTheRoad:
Gas engines are now lasting 300,000 miles and more, yes, even the crappy little car gas engines. A Tundra was recently bought back from the owner (who was handed the keys to a brand new one) with over 1,000,000 miles on it. He brought it in for an oil change and when he came back to pick it up, they told him Toyota Corperate offered him the free new truck in exchange for his 1,000,000 one. Of course he agreed. Toyota is currently dismantling the truck to see how it’s gas engine made it that long. A typical gas engine can last 500,000 miles with perfect service. So the gap is closing between gas vs. diesel. But still, they each have their strengths. I currently drive a VW #DieselGate vehicle. It’s fantastic. And my last VW diesel was 15 years old when I sold it with over 300,000 miles on it. It’s new owner now has over 400,000 on the odo. And then my 1999 motorhome has the very last of the Chevey 454’s (7.4). It has the (new at the time) MPFI and the Alison 4-Speed automatic. It is terrible on gas, but the drivetrain should last beyond the motorhome manufacturers estimated 200,000 life pulling motor home duty. 300,000 miles if it’s normal duty was to pull around a pickup truck. And those are Chevy’s estimates.
So… Whatever you buy, you have to weigh out what works best for you: initial expense, MPG savings/losses, reliability, maintainence and finally the expected length of life. Some say the MB 3.0 Turbo Diesel put to use on a class B one C motorhome should sill get you 500,000 miles. I don’t thing my Chevy 454 will make it that long hauling 10,000 lbs all the time. So, we, all of us, will have to wait and see who far we get with the choices we made…