Wednesday, December 17, 2008

What's best, gas or diesel engine?

Dear Mark,
I sold my 24' Class C motorhome and am shopping for something newer and more efficient, also larger. I'm tending toward the Class B+ Phoenix Cruiser, 27' with two slides. It comes as either gasoline or diesel. I've been told the additional cost for a diesel engine outweighs any gas mileage benefit unless you keep the rig for many years. But I also wonder if other things have been factored in, such as, cost of engine maintenance, cost differential for the fuel type (as gasoline prices rise, will diesel rise at the same rate, slower, faster? What about bio diesel? Is there a re-sale advantage to either one?

I haven't found a discussion of these issues anywhere yet. The dealer I've been working with just gave me the answer above... the diesel is not cost-effective unless kept for many years. I'm an older, single woman, wanting to do some touring with my dog for the next two years or so. I'm expecting various friends to link up for certain legs of the trip. I will appreciate good guidance.

Mark says:
Gas versus diesel is an age old discussion and one that often times gets heated. If asked this question several years ago I would have responded similar to the salesperson because the cost of a diesel model over a gas model was quite significant. Today's RV's offer many gasoline models in the same price range as many diesel products, mainly due to advances in the chassis itself driving the prices upward.

What I can tell you is a diesel will last longer than a gasoline engine so if you plan to keep the RV for a long time it would be worth the investment. I have no idea what is going to happen with the types of fuel or the cost difference between gas and diesel.

Maintenance wise, it used to be that a diesel required less, keeping in mind there are more filters, etc., on a diesel. But nowadays gas engines can go upwards of 100,000 miles before a tune up with nothing more than routine oil changes, air filters, etc.

This probably doesn't help much. If you want some other opinions, I recommend you go to the RVtravel.com forum and post this same question in the appropriate forum. You are sure to get many responses.

7 comments:

  1. Diesel engines generally have more torque, and horsepower, so they get up hills easier and can handle heavier loads. They are more expensive to maintain and fuel will continue to be more expensive than gasoline because they can get about twice as many gallons of gas out of a barrel of oil than they can diesel. So, if money is a big consideration, go with gas, otherwise diesel is best.

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  2. I have owned both--currently a Workhorse W24. I think weight/length determine if you REQUIRE a diesel because of it's extra power--Torque. Under that weight, i think a gasser is better. In the 36/37' range a gasser is ok, above that a diesel is preferred.

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  3. I have a Chevy Duramax diesel pickup truck that I use to tow our 28' travel trailer. Both Ford and Dodge market similar trucks. Here are a few observations:
    -It costs $72.00 for an oil change due to the 3 gallons of oil and expensive filter it needs.
    -ONE tankful of contaminated fuel cost us $6500.00 to replace the fuel injectors. The only advice anyone is able to give us is to only buy fuel from a trustworthy refueling station. How do you do that when travelling?
    -Fuel filters cost $40.00 and need to be replaced every 5000 miles. I do that but it didn't help me much.
    -At fast food drive thrus I have to shut the engine off because they cannot hear me over the engine noise - and the Duramax is the quietest of the lot.
    -All of that being said, there is nothing that will beat the pulling power of these rugged diesels. Mine produces 650 ft lb of torque as opposed to the sub 400 ft lb of the largest gas engine.
    -I reasonably expect to get 250,000 to 300,000 miles on this engine.

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  4. Economics are a weighty factor to the decision of gas vs diesel. However... The "feeling" that the gasser is overworked going up hill is excessively exhausting. It was time, so I replaced my gasser with a diesel (newer duramax) and the "comfort" is overwhelming. Newer diesels are much quieter and do better on the "drive-through" test. My s**t don't... um, the ultra low sulfer and DPFs have dramatically decreased the offensive odors traditionally associated with diesels. During hook up, it smells more like a propane fork lift. Progress is good. There will soon be a "propane-enriched" diesel fuel that improves performance and mileage.

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  5. Here's something to consider - difficulty refueling gas RV. I've a 37 ft class A w/ a tow dolly for my car. I've "knicked" my RV pulling in and out of gas stations twice because except for stations with RV gas lanes (some Flting Js & Pilots) there's not much room for turning.

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  6. Diesel engine initial cost somewhat mitigated by eventual resale. You eventually only pay the difference in depreciation.

    This article is ultimately disappointing, ignoring the real reason people need a diesel engine - the weight of the RV. Fortunately, commenters explained.

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  7. How to weight in on this. I have and old 1980 pace arrow 454 gas, with 77 k miles. when i slow it down i get 8 to 9 mpg. including with my toad on a dolly a honda accord. My former occupation was a gm partsmanager. and dollars and sense gas is the only way to go unless you need over 300 hp. BTW when i go west i go over the rockies on i 70 most of way up i am in high gear, but to be honest i would love to have a 5 or 6 speed automatic trans instead of a 3 speed pete c

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