Gas vs. Diesel RV

Diesel Engines

Diesel engines offer a number of advantages for a big rig like an RV. This engine format offers more torque, which in a nutshell translates into hauling power. That isn't quite the same thing as speed, but it does mean you can tow a car or boat trailer or get up steep inclines without being reduced to a crawl. Also, large diesel engines are built to be robust and to last for hundreds of thousands of miles and tend to have twice the lifetime of a gas engine. It is often thought that diesel engines are always more fuel efficient than their gasoline-fired counterparts, but this is really only the case for smaller RVs. Class C diesels get miles-to-the-gallon comparable to a small SUV, which isn't bad for a 25-foot long vehicle.

On the other hand, diesel-powered RVs are always more expensive than their gasoline-powered counterparts. If you compare the same model of RV with the two different engines, the one with the diesel can cost tens of thousands of dollars more. Furthermore, a lot of older diesel engines are noisy and belch smoke (problems familiar to anyone who has spent too many miles behind a semitruck), and these are a big issue when shopping for a used RV. Finally, big diesel engines of all stripes are notoriously hard to start in freezing weather.

Gasoline Engines

The big advantage of a gas-engine RV is the sticker price. This is a much cheaper format, hands down. Gasoline also costs less than diesel, which becomes important if you camp frequently in places that do not offer electrical hookups. If you are running the engine to provide power, gasoline is always cheaper than diesel. Some RVs can compete with diesels in terms of fuel efficiency, so cheaper fuel simply compounds the savings. However, gas engines simply do not last as long as diesel engines and also lack in serious pulling power.

Which Is Better?

The comparison between RVs ultimately boils down to two factors: how often you plan to use the RV and how long you intend to keep it. The huge extra investment for a diesel engine is justifiable if you plan to own the vehicle for many years and/or intend to make frequent use of it. Then you will get a good return on all that extra money you spent on the diesel engine. Also, diesels are probably a better choice if you intend to regularly pull trailers or some other kind of heavy load. If the RV is for occasional use or if there is any possibility of selling it after three or four years, the amount of money spent on a diesel engine represents a huge loss. In that case, gasoline is the way to go.