New Diesels. Gas Usage Down. Oil Drops. Yippee!

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August 9, 2008

By Bob Difley
It was good news when Mercedes Benz announced that they are building three new SUVs with the new wave of diesel engines that use low-sulfur diesel fuel (the cleanest burning diesels in history). Though diesel fuel now costs more than gasoline, it can get up to 33% more miles per gallon and emissions are so clean that the new diesels are approved for use in all 50 states. They also announced that they have reduced the premium for diesels to about $1,000, competing effectively with gasoline engines and opening the doors to biodiesel fuel on a larger scale. Mercedes diesels are already being used in small Class C RVs (Winnebago’s View and Itasca’s Navion, both about 24 feet, for example) so it won’t be long before efficient smaller diesel engines will move into slightly larger RVs as well. Could it be the age of diesel for RVs?

Oil continued its decline this week, closing at $115.20 per barrel on Friday, its lowest price since May 1. Could it be that the falling price was due to the drop in consumption, down 2.3% from the same period a year ago? Seems so. The DJI rose at the news.

According to MSNBC, “Many analysts have pointed to the $117-a-barrel mark for crude oil as technically significant — a move below this level suggests, they say, that oil’s recent slide is more than a brief pullback. Crude is now down $32 from its high of $147.27 on July 11.” That could be the signal that oil prices have peaked, that we won’t see any more market highs, and speculators with switch out of oil commodities into something else.

So how do we keep oil down? We could reduce our driving by another 2.3%. Doesn’t seem like much. Hey, I’ll bet we RVers have already reduced the numbers of miles we drive by that much–if not more. Now we’ll see whether this new lower oil price will be reflected at the gas pump. Will gas station operators, eager to increase sales from the current slump, also lower their prices to sell more, or keep the extra profits? I’m betting on price drops.

Cutting back usage (demand), and affecting price because of a current over-supply, is what works now to lower prices at the pump. More than increased drilling, more than opening sensitive areas, more than switching over to ethanol or biodiesel—all of which will take time. That is the kind of change we can see right there at the pump. And just maybe (if OPEC doesn’t cut back supply to drive prices up again) we can keep gasoline prices well below $5 a gallon (you think maybe closer to $4?), if we resist the urge to increase our driving mileage just because gas near $4 seems like such a bargain.

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  1. Jerry – Try this link to a forum discussing the popular Winnebago View and Itasca Navion Class C motorhomes that use the Dodge Sprinter chassis and a Mercedes diesel engine:
    Other manufacturers, like Fleetwood, arealso now producing 23 foot to 27 foot diesel Class Cs as well. Google “sprinter” and, the most used chassis for this brand of small Class C diesels and see what else comes up.

  2. Jerry Sanger

    I would like to hear comments about class C motorhomes with a mercedes diesel engine; milage,comfort, reviews, slideouts, etc.

    Thanks, Jerry

  3. Monte J Forney SMSgt USAF(Ret)

    While there are many factors that affect the price of oil on the commodity market I recently picked up a thread that China went on a 9 month buying spree so that they could hoard enough petroleum products to take care of any possible emergency during the games. Now, of course, they have a surplus and are not buying oil which affects demand and lowers price. Have not verified this from a really good source.

  4. Pingback: Hello RV World « Yockster’s Weblog

  5. Carol Colbert

    Thanks Bob and John for all your input. I will probably go diesel with my next RV.

  6. Monte J Forney SMSgt USAF(Ret)

    Reference detune: Would probably screw up emmissions.

  7. Monte J Forney SMSgt USAF(Ret)

    No question Bob, that driving habits effect milage. My wife usually gets 2mpg more than I and never uses cruise, but she refuses to tow. My previous Ram 2500 24 valve 5.9 got much better mpg than the 6.7 but then it was less powerful. The 5.9’s milage, given same driver, improved about 10% over 8 yrs/140K. One interesting approach could be to detune the 6.7 for milage and trade off power for economy since it really is overpowered. Single drive wheels cannot get all that power to the road without winding up the rubber, don’t know about duallies.

  8. Monte – Interesting the comment about mileage going up as diesels get broken in. I’d like to hear from any of you that have or have not experienced that. Also interesting that “culturally most of us lie about our mileage.” I sensed that will the spread between mileage claims for what seem to be similar systems. Driving habits could account for that, but I wonder how much.

  9. Monte J Forney SMSgt USAF(Ret)

    Still not at ease with the premium we have to pay for the ultra low diesel. Understand it has to be refined from the expensive sweeter crude. We are running a 07 Dodge Mega 2500 6.7L getting 18mpg not pulling and 12 with the 07 Challenger 36 foot at 12,600 dry. My diesel guru locally says he is seeing mpg going up as engines are getting broken in. Hard to say, culturely most of us lie about our milage anyway. Bottom line “boogly boogly” is still the only way for bigger RVs.

  10. Hi John – I like that “boogly boogly” sound you refer to. Being a gas guy up to this point, I can’t argue much against a diesel, and my next vehicle will probably be one.

  11. Hey TXBrad. Haven’t heard from you in a while. So what is wrong with cutting back on mileage. I didn’t say anything about not driving, just reducing. If everybody cut back their driving by 10% we wouldn’t need any oil from OPEC. We could do that instantly, which we certainly can’t do with drilling. And look at it this way. If you stayed put in any given place you could do more hiking, more bike riding, more exploring, in the process getting more exercise, cutting down on your fossil fuel usage, and be both physically, environmentally, and economically healthier. You would also be polluting the air less and helping with global warming, The other side of the coin is, I want it all now and I’m going to take it no matter what the cost. Doesn’t sound like a difficult decision to me.

  12. John Christman

    Bob, I think you may have created a debate that you hadn’t planned on. So much for the folks that think the price cuts all have to do with the folks in Congress, etc. I think it is the free-trade agreements or the environmentalists or maybe it’s just the US Forest Service. Come on guys–it’s the world of GREED and the oil exec’s have definitely got the corner on the market there.

    Now for why I prefer a diesel over gasoline–I’ve had both–and would never go back to a gasoline engine on a motorhome. For one thing it has a lot more power/torque for climbing hills/mountains. I love the boogly-boogly sound of the engine. The fact that a diesel engine runs a million or miles is incidental. I doubt my chassis will ever last that long. While I don’t do any of my own service, they are a much more dependable engine with far fewer things that can go wrong. No spark plugs, wires, distributor etc. to change out and contend with. Sure they take a lot more oil than any gasoline engine I’ve ever had 8 qts. versus 22 quarts on my Cummins 8.9L 450HP ISM engine, I wouldn’t trade it for the world.

    Gypsy John

  13. TXBrad

    Come on Bob, Drive less ? Some think this way: camp in their drive ways backyards & don’t drive at all ! Each to their own usage.
    But, R ( as in RV) stands for recreation. Yes traveling all over “our’ roads for many purposes. Even most full timers travel, use a RV to provide income, seasonal work at Parks. It is going to take years to develope fuels, engines, etc. & find a use/ conversion for 1000000 ‘s RV vech. stll in good condition.
    The drilling issue is mostly on federal lands. That federal land belongs to every American, not just Nancy & Duby !! Even, oil under most private land, can not be developed because these GreenWacoos get locals to pass “ordinances” to make it impossible. Refineries would be built by private $ & on private property; but these “save the world filks” have got cities to kill any plans.
    One reason Crude is going down, even w/Libs & Demos on 5 week paid vacation,those in DC are getting more & more support to drill ( % for this is going up NOT down, enough to scare the buyers to start unloading Crude!
    So, while the Libs. fly there Gulf Streams, we must get a horse & covered wagon to RV travel ( conserve fuel)

  14. Joe & Betty

    Does anyone out there in cyberspace know anything about daul fuel conversion?
    We are looking into converting our F 350 diesel daully to diesel/propane. Have heard many good things about this daul fuel combo. Realize you have the start on diesel and switch tom propane and that you can not idle long periods of time on propane so have the switch again to diesel. However propane is several dollars cheaper and burns cleaner and cooler. All comments appreciated.
    God Bless, Joe & Betty Austin

  15. Don Bennett

    Just recently purchased 2008 Dodge Ram 2500 Heavy Duty Diesel and 2008 Keystone Montana 9997 dry weight. I felt this was the right choice. I hope I’m correct in my thinking. Swaped 2007 Tundra 4.7 V8 and Fleetwood 2006 Mallard 5700 lbs. dry weight. Tundra did a decent job but we needed a larger RV. WE shall see if it works, one thing for sure I’m not letting the situation (with fuel) keep my butt at home!

  16. Bob Difley

    Carol – There are many readers of this blog who have a great deal more experience and knowledge on diesel/gasoline comparisons than I do, and I hope some of them will reply to your question an provide an informative debate (a couple already have).
    I am far from being a techie, but my understanding of the advantages of a diesel are that they last longer and get better mileage than gas powered vehicles. The disadvantage is that they cost more. However, the spread between the costs of gasoline and diesel engines is narrowing, and diesel fuel is becoming cleaner and less polluting so the future of engines points to diesel. In addition, diesel engines–without any modification–can burn biodiesel fuel, the future of diesel fuel as we phase out petroleum-based fuels. Gasoline engines, however, need to be built as flex fuel engines (or converted at greater expense post-manufacturing) to be able to burn an ethanol blend greater than 10%. Ethanol blends of E85 (85% ethanol) are expected to be available nationally within a very few years.

  17. Carol Colbert

    Bob, I am fairly new to RVing and very new to the gas vs diesel debate. I currently have a Class C 24′ gas. When I do trade up and go full time should I look at diesel and why? Thanks.

  18. Fred

    My 2005 Dodge Ram 2500 diesel pickup gets 22 mpg not towing. I pull a 32 foot, 12,000 pound fifth wheel at 55-60 mph. Total weight is 16,300 lb. Rounding off, under very best conditions, 15 mpg. The worst was traveling through the Rockies at 11 mpg.

  19. Ken Hall

    We have an ’07 Alfa See Ya Sooo Long (long slide out) with a Mercedes 330 diesel engine. With 7,000 miles in it, pulling a an ’06 Saturn Vue, we are getting 9.6 MPG