02/07/12

You’ve found the motorhome of your dreams and just one question remains: gas or diesel? Most Class A manufacturers now offer at least one model with a diesel pusher engine, forcing the question of which type is indeed better.
The 2001 Ultimate Freedom diesel pusher from Winnebago offers all the comforts — and power!

A good rule of thumb is to seriously consider a diesel engine for any RV more than 35 feet in length. This is doubly true if your driving adventures take you through much hilly terrain, where extra power is needed. The reason has to do with the length of the driveshaft and its ability to transfer power to rear wheels. Of course, I just test drove a 37-foot gas-powered Coachmen Santara and it did just fine, but generally the rule is still a good one.

Many of the old stigmas of the smelly, hard-starting, noisy diesel engine still apply, but their effects have been greatly reduced. Today’s diesel engines are quieter, harder working and more efficient than every before, as best exemplified from the latest offerings from Cummins and Caterpillar. With the ear-mounted engines of today’s diesel pushers, noise is simply not a negating factor. This is a different story for your tow vehicle, however, where you’re just a matter of inches from an engine that isn’t afraid to howl. The smell is also not the greatest, and cold-weather start-up problems can still hamper diesels when the temperature dips below 30 degrees. However, electronically-controlled engines, properly maintained, shouldn’t really be hard-pressed until right about zero degrees.

Cost is another factor. Diesels are simply more expensive to buy, whether it’s for your RV or tow vehicle. Fuel costs also run higher, but are somewhat offset by better fuel economy than its gasoline counterpart – a very big perk for a motorhome struggling to earn double-digit miles per gallon. Unfortunately, winter creates another set of fuel problems for diesel owners. Icing and gelling in the fuel tank, associated with the changing of temperatures, often necessitates special care. A number of fuel additives are available to remedy these problems if they should occur. Travelers also have to be sure their diesel fuel is fresh since it doesn’t share the popularity of unleaded fuels, and thus, runs the risk of being old. It’s probably best to fill up along the interstate, where the hordes of 18-wheelers keep the diesel supply fresh and the turnover rate higher than at other locales.

Your diesel pusher will probably need less routine maintenance over time (no tune ups or spark plug changes necessary), but when work is required, it will definitely cost more and not every shop can do the job. A $100 oil change is very possible. However, diesel engines are extremely durable and should last a long time. Stories about pickups besting 500,000 miles are not uncommon. This workhorse reputation should serve you well come trade-in time.

The best answer to this eternal question probably lies in a comprehensive test drive. Compare your gas and diesel models for acceleration, hill power, noise and smell. Be realistic about the costs as well as your commitment to diesel fuel and filling up with the big rigs. Then make your decision and never look back.