Do you put diesel in a gas truck?

Discussion in 'Performance & Fuel' started by rileyjr16, Sep 16, 2013.

  1. rileyjr16

    rileyjr16 New Member

    Alright so we all know that they have products like seafoam and Lucas to clean out our fuel injectors. Whenever I was little I always remembered my dad (very smart with vehicles) putting maybe a gallon and a half to 2 gallons of diesel fuel in his 1992 GMC Sierra with the 4.3 V6. He always told me that this was one of the best ways to help clean out your engine and keep the system clean. I'm just curious if anybody ever runs diesel occasionally through their trucks mixed with gasoline. I only do this every now and then and since I have a fuel injected engine instead of TBI, I don't quite have the ratio that my dad used to use. I just filled up 23.178 gallons of gasoline and about 3/4 gallon of diesel fuel.

    What can this hurt?
  2. tbplus10

    tbplus10 Moderator

    Never ran diesel with the fuel but some additives do have a chemical make-up similiar to Diesel.
    Possible consequences might be an oily coating in the cat convertor, but it should burn out quick with the temps, and oily residue on pre cat sensors.
    But on the other hand it should offer lubrication to valve seals, seats, and injectors.
  3. rileyjr16

    rileyjr16 New Member

    That was also another bonus I remember hearing about. Lube.
  4. reggiecab2000

    reggiecab2000 Member

    what generation is your father from?
    sounds just like mine lol
    My dad has always told me the same thing!
    but i have yet to try it...
  5. rileyjr16

    rileyjr16 New Member

    The Dwight D Eisenhower generation.
  6. yotchie

    yotchie Member

    i have heard of the diesel fuel. I think the amount seems a bit high but if the results are positive then all the power to ya. i have also heard a small amount of atf fluid is good for injectors but i haven't tried it
    Last edited: Sep 16, 2013
  7. tbplus10

    tbplus10 Moderator

    Ive used ATF fluid in a carburated engine to loosen stuck lifters.
    It also works well in Mazda RX7 rotary engines to condition the wipers on the rotor, stops excessive oil burn.
  8. rileyjr16

    rileyjr16 New Member

    So not recommended for use in my truck (ATF)
  9. Pikey

    Pikey Moderator

    Back in the day ATF was ok. But, I have heard that it can mess up your cats and O2 sensors. I don't know if it is true or not. I run TC-W3 2 cycle marine formula in every tank with a 5 gallon to 1 ounce ratio. It is said that it lubes and cleans injectors, fuel pump, and valves. I have been running it approx 6 months and have seen an increase from between 13.5-15.2 mpg to a solid and consistent 17.4 mpg in the city. Not to mention a smoother idle
  10. rileyjr16

    rileyjr16 New Member

    Heck I need me some of that
  11. kinson33

    kinson33 New Member

  12. dsfloyd

    dsfloyd New Member

    This is what I do ^^^^^

    I have heard of the diesel thing too but dont remember the mix ratio.
  13. dobey

    dobey Member

    Ethanol is a natural cleaning agent, so you don't really need to worry about adding diesel as a means to clean the fuel pump and injectors. Petroleum is also a natural lubricant, and how the fuel pump is normally lubricated. If you want additional cleaning and lubrication, then a standard cleaner/lube mix-in like the ones from Lucas or STP will generally suffice. If you want to add additional lubrication, to make up for the loss of any lubrication in a 10% ethanol mix, or with E85, then adding in some "top end lube" wouldn't be a bad idea. All the drag racers running methanol or ethanol, have to run it to help out with lubrication as the alcohol doesn't lube as well as gasoline does.
  14. Pikey

    Pikey Moderator

    This is true. But, ethanol also causes corrosion. You are correct that you can use a STP or Lucas additive. But, TC-W3 2 cycle is much cheaper to use. I bought a gallon of it for $22. I have used it with every fill up for the last 6 months and I am barely half thru the gallon. You can get it cheaper if you don't buy the synthetic. I think that I saw somewhere that walmart has it for $14 a gallon.
  15. ChevyFan

    ChevyFan Administrator Staff Member

    Yeah, on first thought there is something to this ... but I wouldn't do it to any vehicle of mine.
    [MENTION=14295]tbplus10[/MENTION] is right. Diesel and some of the fuel system cleaners do have a common origin, but I would want to talk to a chemical engineer before I would recommend this. Plus, why not just get one of the tried-and-true cleaners like SeaForm or RXP instead of trying to figure out the proper way to dilute it?
  16. tbplus10

    tbplus10 Moderator

    Gasoline used to have decent lubricating qualities too, before the govt. required unleaded fuel.
  17. kinson33

    kinson33 New Member


    Giving that a shot, off to walmart I go! Any brand preference for the two of you that already do this?
  18. Pikey

    Pikey Moderator

    I use pensoil full synthetic marine formula.
  19. phoebeisis

    phoebeisis New Member

    Marvel mystery oil is supposed to a bit like heavier diesel
    read that somewhere
    The diesel in gas-real oldschool
    2 gallons per tank-seems a bit high-
    probably would use less-maybe a pint or so per tank if I was going to do it
    EASIER to just use sea foam techron etc
  20. rileyjr16

    rileyjr16 New Member

    Maybe my figure was a little high. He said today that he never put over a gallon of it in his truck. I was young

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