gas vs. diesel engines

Discussion in 'Shop Talk' started by Ken in Maine, Jun 24, 2005.

  1. Ken in Maine

    Ken in Maine Well-Known Member

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    Been looking around at new trucks lately, especially with the GM discount. One salesman suggested that because I drive 25,000 miles per year and pull a stock trailer for a good number of those miles I should consider a diesel engine rather than the vortec 6000.

    I'm looking at the Sierra 2500HD with bells and whistles ( this may be the last truck I buy). There is about a $5500.00 difference between gas and diesel. The diesel seems to make more sense but thought I'd get more input.

    Thanks for your help!
     
  2. fordy

    fordy Well-Known Member

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    ...............Your comparison should BE....between the 8.1 gas vs the Diesel , not the 6.0 . You can get either gas or diesel with the Allison . From the reading I've done on rv.net , etc. the 8.1 will get between 7 to 10 mpg while towing . Unloaded with a 3.73 axle ratio might get as high 14 or so . The Duramax will get 10 to 12 towing and as high as 21\22 unloaded . But an oil change requires 15 qts. or so , and oil\fuel\air filters are always more expensive . If , we accept the assumption that Diesel will continue to rise in Price , You will never recoup the cost differential on the initial purchase or on the milage differences between gas and diesel . I would drive Both and spend some time with current owners and allow their insight(s) to guide you before you make your final choice . In addition , if you will be pulling a 5th.wheel I'd Opt for the Diesel especially , IF , you will be doing any Rocky Mountain driving . The turbo charged diesel will perform at altitude as well as sea level whereas the 8.1 will loose both torque and HP for every 1000 feet above sealevel that you drive . fordy.. :)
     

  3. farminghandyman

    farminghandyman Well-Known Member Supporter

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    my son jsut bought a used Ford diesesl with the power stroke pulls a fifth wheel trailer, he was using a old Jeep with a 460 we put in it, the gallons per mile doubled between the two trucks loaded and unloaded, he can now cost effectly drive, yes the cost of diesel repairs is greater, but the life of the motor may be in the 400,000 to 600,000 range if traken care of, there are a lot of the diesesl out there that have joined the million mile club,
    If I could aford a diesel I would have one,
     
  4. Ken in Maine

    Ken in Maine Well-Known Member

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    All of my driving will be east of the Mississippi, no BIG mountains just lots of hills. The salesman was saying that the fuel mileage with the diesel would stay constant around 17mpg loaded or unloaded. I currently have a 1/2T Sierra with 5.3 vortec. It gets 17/18mpg unloaded but hook on the trailer and it drops to 12mpg. Another point he made was that at 20,000 +miles per year the gas engine would be worn out before it was paid for (looking at 60 months financing), while the diesel would just be getting broken in. I have found with my present truck that I replaced the head gasket @ 92,000 and have had two brake jobs in 14 months.

    I bought my truck used with 45,000 and have put on about 90,000 in a little over 3 years.
     
  5. fordy

    fordy Well-Known Member

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    ..............(1)the fuel milage on the duramax WILLNOT stay the same!! UNless , of course the combined weight of trailer and load is less than say a 1000 pounds and creates almost no wind drag .
    ...............(2)most gasoline engines made today are quite capable of 200,000 miles IF they receive regular service and ARE not operated in a continuously overloaded condition . 20k miles ayear should be good for 10 years of service .
    ...............(3)just me But I'd want that Allison auto with the 8.1 and a 3.73 axle ratio which is capable of hauling large or small loads and will provide a margin of extra towing capacity .
    ...............(4) IF you have decided that the 6.0 has sufficient capacity to meet your needs the Duramax is really a waste of money . On the Other Hand , I'd buy the diesel simply because that is what I wanted and could afford . fordy.. :)
     
  6. Darren

    Darren Still an :censored:

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    I've got a couple of Fords with good 6.9L diesel engines. The body has always gone before the engine did. The 6.9 and early 7.3L (non-powerstroke) are mechanical setups without the electronic injection systems that came later. They're easy to troubleshoot if you do have a problem. If I was in the market, I would look for a 93 or earlier Ford w/ a 6.9/7.3L diesel that had a good body.

    I'll probably transplant one of the 6.9L into an F600 4x4 later. The 6.9L engines were also used in the IH trucks rated at 26,000 GVW. That goes to show what the manufacturer thought of the engine. Ford in the early years was limited in the GVWs they could offer with the engine by the contract with Navistar. Navistar didn't want Ford competing with their medium duty trucks.

    The Allison in the IH trucks behind the 6.9/7.3L was rated for around 30,000 GVW. With the older Fords the C6 auto they used was the weak link. If you got 120,000K out of it, you were doing good.
     
  7. unioncreek

    unioncreek Well-Known Member Supporter

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    You can't really look at maintenance cost as being more with a diesel. My Dodge with the Cummins takes 12 quarts of oil double that of a gas engine, but I can put 6000 to 7000 miles on it between oil changes. Fuel filter costs more, but other costs are pretty muc equal. If you're pulling a trailer you'll want to go with the diesel. I pull a older 27 foot fifth wheel with both a Ford F250 with a 460 and now with a Dodge 2500 with the Cummins, there is not even a close comparison. I can pull a 7% grade with the Dodge at 55 mph, the Ford would drop to 35 mph.

    I would check around on the different diesels Ford, Dodge or Chevy, I'm not stuck on one make. Just make sure you buy the make that you like the best and you'll be happy with it.



    Bobg
     
  8. jgbndaudio

    jgbndaudio Well-Known Member

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    Hello,

    I strongly suggest you go with the diesel, because a diesel engine can run on other types of fuel. Alas a gasser only runs on gas. Since it's likely the cost of fuel is going to continue to go up this may be a benefit to you. Here are some sites to check out and see what I'm talking about. I'd be happy to answer any more questions you may have.

    Scotty


    http://www.greasecar.com/

    http://www.greasel.com/


     
  9. TheBlueOne

    TheBlueOne Well-Known Member

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    First, salesmen work on commission. The more expensive the truck, the higher commission. Of course you need the diesel; you also "need" the power moonroof and the Bose stereo and the....

    IMO, since you spend at least half the time towing you would be happier with the Durasux diesel. With the diesel fuel price increases expected because of the switch to low sulfer fuel you will never re-coup the initial investment, however you will enjoy the increased power in the hills and the better fuel milage while driving unloaded.
    As far as the gas motor not lasting as long, that's debatable. The Durasux diesel is an Isuzu motor built by GM Powertrain in Moraine, OH. There have been ummmm......numerous "issues" with the motor. The 5.3L & 6.0L are updated versions of the ancient Chevy small block. While it theoretically won't last as long it will be MUCH cheaper to repair. That being said, there are more diesel Chevy/GMC HD's (same truck, built on the same line) built here in Flint, MI than gassers, probably a margin of 2 to 1.
    Anyway, BUY THAT TRUCK! The Ford Powerstroke is a better tow vehicle, but we need the business!

    There's also talk of the "GM Employee Discount" promo now continuing through the month of July instead of ending the first week. Market share for the month of June is up to 30.7%! The "suits" in Detroit are loving it.
     
  10. Darren

    Darren Still an :censored:

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    Jgbndaudio had a point. With a diesel you have the option of using an alternative fuel without (normally) making changes to the fuel system. If you go to biodiesel for year round use, you may need a fuel heating system. Diesels will run on home heating oil or a kerosene/diesel or jet fuel/diesel mix in the winter and heating oil or vegetable oil in the summer. You can also store diesel for long term and use it years later. I'm using diesel I paid around a $1.20/gal that's five years old.

    Diesel goes through seasonal price changes that result in cheaper prices (normally in the fall before cold weather starts, before heating oil prices go up and the heavy gasoline demanding summer vacation driving is over) so you can save money if you stockpile. Used fuel oil tanks aren't that expensive.
     
  11. Ken in Maine

    Ken in Maine Well-Known Member

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    Thanks for all the input!
     
  12. golfball

    golfball Member

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    I have the DuraMax diesel in my chevy pick-up (SWB) and have driven it with an empty bed and driven it with the bed filled completely with Watermelons. I get the same fuel mileage loaded or empty because I tend to stay below 65 miles an hour loaded with Watermelons.

    I have the 3:73 ratio - 4WD and am quite impressed by the performance of the Duramax Diesel.

    Recently, I had to pull an empty 18 foot flat bed utility trailer out to West Memphis, Ark. to retrieve my brother's pick-up due to the fuel pump going out after around 120,000 miles. Himself and his wife was broke down in a bad area so naturally I hot-footed it out there to help him load it up. I had to go about 135 miles one way (270 miles there and back) so my fuel usage was factored by speed and weight.

    With a 3:73 ratio, you maximize speed - power - fuel MPG around 60 to 65 M.P.H. Once you go over 65 M.P.H., you start losing MPG through engine overspeed.

    Since I was pulling an empty wagon on the way to Memphis, I should not have lost any MPG. Yet I was traveling at a hurried pace due to the circumstances and burned way more fuel than I would have normally consumed by maintaining a steady pace around 60 M.P.H.

    I left the house with a full tank and arrived in West Memphis showing just under 3/4 full. After my brother's truck was secured on the trailer, himself and his wife were safely loaded, I fueled up at the Flying J Truckstop in West Memphis, Arkansas. I drove back home keeping my speed under 65 while maintaining a steady, leisurely pace.

    When I arrived at the house, my fuel guage read above 3/4 of a tank! I had consumed less fuel pulling a loaded trailer, than I used hauling ass with an empty trailer across the Arkansas Delta region.

    This is with a 2004 Chevrolet Silverado 2500 HD DuraMax w/Allison 5 speed Automatic.

    Just my two cents.