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Marvels Mystery Oil in engine?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by hec24, Oct 24, 2019.

  1. hec24

    hec24 New Member

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    Has anyone ever put Marvels Mystery Oil in their engine? Notice any difference in mpg or horsepower?
     
  2. bisco

    bisco cookie crumbler

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    i think some have, if you can find the threads, but i don't recall any confirming positive results.

    but for every product, their are a few true believers
     
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  3. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    If it increases MPG or Horsepower then why don't they put it in the crankcase at the factory?
     
  4. Grit

    Grit Senior Member

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    If anything, it will only restore hp and or mpgs lost.
     
  5. audiodave

    audiodave Active Member

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    Been using it for almost a year. Seems to give couple miles extra a gallon. Same trip mostly freeway gave me 47mpg without and 50mpg with it. It's inexpensive to try.
    Can't say any difference in power.
    2004 with 255,000 miles and a 3 year old rebuilt battery.
    Posted via the PriusChat mobile app.
     
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  6. sam spade 2

    sam spade 2 Senior Member

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    MMO is just a VERY thin oil and has some limited solvent properties.

    It is NOT appropriate to use in a new engine because it would do nothing worth while.
    It might tend to loosen stuck rings in an old engine......might.
    I used it once in an old pickup truck poured slowly down the intake and it had a DRAMATIC affect on oil usage.
    But that vehicle was over 30 years old and had near to 100K miles.
     
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  7. frodoz737

    frodoz737 Top Wrench

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    Snake Oil.
     
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  8. bisco

    bisco cookie crumbler

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    my father swore by it. he put that $h!^ on everything
     
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  9. ASRDogman

    ASRDogman Senior Member

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    If you change your oil as you should and use synthetic as you should it probably be of minimal help. Can't hurt though.
    As started above it could help keep the rings clean.
    I use it in the fuel tank every 5 or 6 tanks and it helps keep the injectors clean.

    I used it a lot on my van I could tell the difference. Minor mpg improvement possibly, but my city driving was 16-18 mpg,
    and highway was 20-25, so it was hard to really tell. But I could feel it when accelerating and at idle, it was smoother.
    That's when I knew it was time to use it.

    But results may very. :)

     
  10. sam spade 2

    sam spade 2 Senior Member

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    Actually it CAN hurt. If the overall viscosity of the oil goes BELOW the minimum required.

    AND MMO was not designed nor intended to "keep injectors clean".
    There are other products that ARE designed for that: Techron for instance.

    Any kind of oil in the gas will tend to increase carbon deposits in the combustion chambers too.
     
  11. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    I'm just trying to realize my lifelong dream of appearing in @Grit 's signature.....
     
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  12. Ed Beaty

    Ed Beaty Active Member

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    "I'm just trying to realize my lifelong dream of appearing in @Grit 's signature....."

    A truly worthy endeavor! ;)
     
  13. ASRDogman

    ASRDogman Senior Member

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    Well, I have only been using it on my van for 250,000 so I may not be accurate.
    And a few hundred thousand miles on 4 or 5 other vehicles since the early 80's.
    Since for the Prius they call for 0-20, it's hard to believe 8 ounces in 4.5 quarts are going to hurt it.
    But what do I know?
    I just know that when I use it when the idle starts getting rough and slight hesitation on acceleration,
    at 1/4-1/2 tank it clear up after putting in the fuel.

    Again, results may very per use per vehicle.

     
    #13 ASRDogman, Oct 25, 2019
    Last edited: Oct 25, 2019
  14. Rmay635703

    Rmay635703 Senior Member

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    A start would be being allowed to see his profile page.

    ah the inner circle