Steve Savage submitted this article to RVtravel.com when he was a Master Certified RV Technician with Mobility RV Service.
Should I buy a motorhome with a gas or a diesel engine? Good question. Not a simple answer.
In general, I do not think one type is always better or worse. Rather, I encourage buyers to consider size and weight. When you get into larger motorhomes — which I define as more than 34 feet and certainly more than 36 feet — I tend to think in terms of diesel power. As motorhomes reach those sizes, they need more torque or grunt than gas engines can achieve.
The biggest advantages of diesels are their power, along with better mileage and less complexity. The disadvantage comes when repair time rolls around. Anything diesel is heavier and costs much more to repair. Some folks also have very little tolerance for the smell of diesel fuel, and filling at truck stops virtually guarantees diesel on the carpet. The normal life expectancy of diesel engines is 500,000 miles, an irrelevance for most owners given how long motorhomes are kept before being traded.
The advantage of gas engines is their much lower cost compared to diesels — they average $20,000 less. The industry says life expectancy is about 200,000 miles, and I think their longevity and reliability improved dramatically starting in about the year 2000. At times it is easier to find gasoline than it is diesel fuel, although this is much less a problem than in years past.
Buy diesel if you need the power. I question that diesel power is ever necessary in any class C motorhome, where the current lineup of GM and Ford power trains do very well. I also see little advantage for diesel in shorter class A coaches, unless cargo carrying capacity (CCC) is very large. I think many consumers have gone overboard with the weight issue and seldom use the thousands of pounds of cargo carrying capacity they demand.
Snob appeal? Diesel wins, hands down!