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Marvelous Mystery Oil

Has anyone heard of this product? I recently have and bought a bottle of it to try in my gas tank. It supposed to be a great product. It was first made in 1923 according to their web site. Thanks!

Tom and Ray have consistently said over the years that these miracle additives are bunkum. I have seen no evidence any of them do anything except transfer your money to the manufacturer. Do what you want.

The only additive I’ve had success with is Seafoam.

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Marvel oil is basically Dexron ATF with some oil-of-wintergreen in it. It makes a great all-purpose light oil, including top oil, sewing machine oil, gun oil, fishing-reel oil, motor oil, you name it…

There’s a time and place for additives and don’t expect MMO to be the miracle product that cures every ill.
I have used MMO with some success to cure a rattling, sticky valve lifter or lash adjuster problem but that’s about all I would recommend using it for.

You should leave it out of the gas tank. Your car is not a 2-stroke and you don’t need to be adding stuff to the tank with additives that can cake in the converters.
Once in a blue moon won’t hurt anything but it’s also not necessary and won’t accomplish much, if anything.

The mystery is does it really do anything? The good point is, it is not expensive and I have never heard of anyone who had it do any harm, other than what it cost.

My suggestion is go ahead and use it as recommended on the can and don’t bother buying any more.

Thanks for your reply. I appreciate it.

Thanks for your feedback.

Many years ago, I regularly used it with a car that had a tendency to “ping” under load during the summer months. Adding some “top oil” to the gas can help to prevent damage to valves from pinging, and was a good temporary measure until I had the time to replace the spark plugs and do other work to stop the pinging. MMO worked fairly well as a top oil in that car from the '60s.

However, that was in the days prior to catalytic converters. If you did the same thing nowadays, you would wind up with a fouled converter and a huge bill to replace the converter.

As ok4450 suggests, adding a pint of MMO to the crankcase could help to free up sticky valve lifters, but I would recommend that you avoid adding it to your gas tank except for perhaps a very occasional use.

As Caddyman points out, it is basically ATF. As we learned back in the old days, ATF is pretty good at cutting through sludge in the oil passages, so adding it to the oil occasionally was effective at keeping hydraulic lifters healthy back in the 60s and 70s. That is not such an issue any more.

The only thing I have seen Marvel Mystery oil used for in the past 30 years was air tool oil. You squirt a bit into the inlet of your air tools when you put them away, or better yet, use an in-line oiler to mist it in to the air supply to keep the air motors clean and lubricated. If you look at the little bottle of oil that comes with a new CP air tool, it says “Made by Marvel Oil Company” on it.

I would not put it in my gasoline. There are better products, like Techron, for fuel systems.

I’ve read the posts below. I’ve used it from time to time over the last 37 years in various cars. Currently have a 2005 camry and a 2004 accord. I put it in the gas to keep the lifters quiet. Haven’t had an issue with using it. I do it once or twice every year for a few tankfulls.

What type of logic is oilman using? I also use Marvel for air tools.

I find the color irresistible. I don?t use it for much, but I need to have a can because it is so pretty.

i put in the gas in mins WOW !

I put in gas. wow is all i’m saying

@Harvey_Manwarren this is a 9 year old thread…let it remain dead please


i put in the gas the car never started that fast in it life

just stuff another day . 9 years or 9 days - or 9 hours

I always wondered if MMO was basically ATF. Learned something today.

I have used ATF in the engine oil to free a sticking lifter. So I guess MMO would be good for that!

Of course you put in gas. That is what makes the vehicle run.