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How "Liqui Moly" Molybdenum disulfide oil treatment could help "start-stop" engines

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by Mike500, Nov 26, 2013.

  1. Mike500

    Mike500 Senior Member

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    I'm NOT one to be sold on oil additives and supplements, but I believe that molybdenum disulfide of MoS2 can really help "start-stop" engines like those on the Prius.

    Molybdenum disulfide has been known and used for ages in lubricants, and I believe that a certain amount has been already added to quality motor oils like Toyota synthetic and Mobil1.

    I can see how it helps and clings to the metal wear parts to the engine during "drain down" when the oil pump is not running.

    And, with the 10K oil change on the Prius, it is cheap insurance.

     
  2. mikefocke

    mikefocke Prius v Three 2012, Avalon 2011

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    I might be helpful if you explained why and on the basis of what data you are so convinced. Most oil additives are snake oil. And if it were the cats meow, of course oil formulators would be using some. But sometimes more is not better.
     
  3. Fore

    Fore Don't look back!

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    That's sound thinking and advice!
     
  4. rdgrimes

    rdgrimes Senior Member

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    On a Prius, the ICE is spun up before any gas or spark is applied, hence it is fully lubricated before it fires. Its a completely different scenario from any other engine starting, and virtually no wear results from starting. Some additives might possibly reduce wear from starting, but we're talking about the difference between a gnat's fart and a gnat's belch. There's not much chance that the additive would ever save enough wear to justify its cost. (or ANY cost)
     
  5. Air_Boss

    Air_Boss Senior Member

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    Historically, the primary use of "moly" was in manual gearboxes and differentials, as opposed to engine oil.
     
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  6. Stevie

    Stevie Junior Member

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    perhaps the Castrol Magnetec would be the way to go ?
     
  7. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Call me crazy, but perhaps the oil the engineers who designed the engine specify?
     
  8. Robert Holt

    Robert Holt Senior Member

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    Yes--that was my use in 4 manual transmission cars. Some had really balky shifting beforehand and those noticeably improved with the Moly Slip Lube I added. However, it was a fairly thick black goop that would possibly be screened out by an engine oil filter, and I learned when adding some to a Honda Rebel tranny that it completely ruined the wet-plate clutch because it would now slip rather than grabbing when released! Sigh.
     
  9. The Electric Me

    The Electric Me Go Speed Go!

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    Here's the logic I'm applying as to why I'm NOT going to use any Oil Additive with my Prius.

    Toyota makes good engines.

    I believe with just regular maintenance, The Prius engine is likely to outlast many other major components. In other words, additive or no additive, benefit or no benefit, my guess is the useful life of my Prius will end way before the engine get's close to any catastrophic failure.

    Occasionally we get a thread or two where somebody has suffered an engine failure at some mileage or point in their Prius's life but generally it seems the engines do exceptionally with or without an additive.

    So I'm not really going to debate whether a "Molly" additive is potentially helpful...I generally think the quality of Toyota's engine, coupled with maintaining regular maintenance, with a good quality oil is more than enough to keep the engine running well and viable for any period of time I would be keeping the vehicle.
     
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  10. Cape Codder

    Cape Codder Junior Member

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    It may be totally unnecessary to add anything .
    The oil specs that Toyota has specified are state-of-the-art.
    0W-20 synthetic oil is extremely fluid, even at low temp extremes, and being synthetic, handles high temp extremes very well. 0W-20 moves VERY quickly through the engine as soon as it is started.
    Conventional oils such as 10W-30 or 10W-40 or even 5W-30 move far slower at cold temps. Until the oils gets between moving parts, there is a chance for wear. Yet, Toyota engines using the 5W-30 conventional oil easily go 200,000 miles.
    The advantage with synthetics is that they do retain a micro-coating over a long period of time even though 99.999% drains into the sump. That micro-coating still lubricates very well until the oil is pumped around the engine. The synthetics achieve this better than conventional oils.
     
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  11. PriusGuy32

    PriusGuy32 Prius Driver Extraordinaire

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    I added Liqui-Moly into my last vehicle... I added 1/2 can to the oil sump (7 quarts of oil). The SUV had massive, typical GM, piston slap. It quieted it down a little. It made the oil very dark (read: dirty) looking and from what Ive read that type of molybdenum isnt even the right type to use as an oil additive.

    Any which way, my variable valve timing actuator failed during that OCI. Did it have something to do with the liqui-moly?? I do not know. All I know is the VVT actuator cost me $43 to replace and took me about an hour of my life Ill never get back.

    Would I put it into my Prius, which are known to have achieved 300,000+ miles with no sweat off its brow?? Nope. Ill use the other half of the can in my lawnmower.
     
  12. wjtracy

    wjtracy Senior Member

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    We also have to be worried about metals getting onto catalytic converter which could reduce eco-performance. Someone would have to assure us that moly is OK for a Prius. Now if I had a problem with older Prius, I might be inclined to experiment.
     
  13. ETC(SS)

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

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    TEM is right.
    If you change your oil even semi-regularly and monitor oil volume in between, then your ICE is almost 100-percent guaranteed to last for the life of the car. Even an ICE that smokes like John Wayne will last tens of thousands of miles...TRUST ME.
    If you drive in a state without a VET, then you get to see where all of the cars that don't pass emissions in the other states wind up after you sell them off. :)

    The Molly-be-dammed stuff really isn't snake-oil per-se, and it probably won't hurt your motor.
    Technically?
    It might even help measurably...like if you keep the car for 400,000 miles, but since most people sell their cars looooooong before that there's really no point.

    Besides...if you trash a motor, then you can get a used replacement from a wrecked car for about $500.

    YMMV. :)
     
  14. dbcassidy

    dbcassidy Toyota Hybrid Nation, 8 Million Strong

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    Not buying the "Moly" treatment for the ICE. Stick with what the bible (owners' manual) recommends.

    Save the money you would have spent on moly and buy some beer!:)

    DBCassidy