Seafoam vs Marvel Mystery Oil! The Ultimate Showdown!

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  • Published on:  Tuesday, May 9, 2017
  • I test the legendary Marvel Mystery Oil and compare it to Seafoam results from previous videos. You get to decide which product is superior!
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  • cjhmarine0621


     5 hours ago

    Why didn't you add it directly to the fuel

  • Loujean Adams

    Loujean Adams

     20 hours ago

    I like the IV you rigged up! :)

  • Kristopher Hasenbuhler

    Kristopher Hasenbuhler


    Use both

    One then the other!

  • PracticalTech



    It's really hard to say which one performed better, as the tests were unequal. Also, you got the "after" compression numbers reversed between hot and cold on the MMO test. Further, there may have been an inconsistency in the cranking of the engine on the "after MMO" hot compression test.
    It is clear the Seafoam test was on an engine that was in worse condition to start with, so there was much more room for improvement... Perhaps it cleaned some junk out of the ring lands and allowed or helped the rings to seat better, thereby improving compression.
    Somebody else mentioned the MMO visually appeared to do a better job of cleaning and I think I agree, but that doesn't mean the actual results are better, as it is a subjective assessment.
    Either way, it appears they are both good products that do a very good job of cleaning the inside of engines.
    Thank you for your time and work to make these videos.

  • Chris Chris

    Chris Chris


    Marvel Mystery Oil....Still smells better!

  • Revanth Reddy

    Revanth Reddy

     2 days ago

    The carbon buildup causes the compression to increase as there is less space for the compressed air fuel mixture in the compression stroke. This higher compression ratio than what the engine is designed for, causes knocking. The reduction in the compression is actually a good thing. Good thing would be to see if you have any compression pressure numbers when this engine was new.

  • Ron Thompson

    Ron Thompson

     3 days ago


  • Ron Thompson

    Ron Thompson

     3 days ago

    My college teacher use to have us put a few drops in the air tools work great .that's when I was first inderduce ,everyone should keep a bottle around is has so many use.

  • David Winrow

    David Winrow

     4 days ago

    Can you test some of these products like the (cleanboost gold fuel additive) plus they have motor oil. A buddy of mine swears by these products.

  • Kraig Gustavsson

    Kraig Gustavsson

     4 days ago

    Might try mixing mmo in fuel and running longer.

  • Hearkening Sojourner

    Hearkening Sojourner

     4 days ago

    Marvel is definitely better on cleaning and loosening rusted parts.

  • James Paul

    James Paul

     5 days ago

    That was hilarious at the end. So calmly stated, "I have never jb welded a cylinder head. So I destroyed a cylinder head. With a grinder I cut straight through" GOLDEN!

  • Drew Cuva

    Drew Cuva

     5 days ago

    I love your videos. Can you do a video testing pump gas vs Trufuel, the engineered gas? Run each one and see which has less carbon deposits etc.

  • Ken Hurley

    Ken Hurley

     5 days ago

    Airplane mechanics will use MMO in the oil and gas if the planes compression is low. After 4 hours of running an engine (the planes is anchored so it can't move) the compression is within the engines specs! Pretty cheap fix.

  • Gary Brown

    Gary Brown

     5 days ago

    @Dontlookback05  we usto dump ATF straight down the carburetor with the engine running at full THROTTLE yes it would smoke and die then we would let it sit over night in the morning restart and the compression would return

  • Mountain Man

    Mountain Man

     6 days ago

    Mystery oil is safer to use.

  • Joey Simunds

    Joey Simunds

     6 days ago

    Daddys always been a diehard Marvels man. But nice to see NewTech gave us Seafoam, thankyou for thaking the time and distributing your knowledge and showing the work put into finding it!! Weekend well spent eh?

  • DMTrip Report

    DMTrip Report

     6 days ago

    What a great channel!

  • Gary Mies

    Gary Mies

     6 days ago

    I am old school marvel

  • Eric Hansen

    Eric Hansen

     6 days ago

    Hello can you do Bytron the Russian seafoam against seafoam ? I always wondered