Marvel Mystery Oil

[87 HJ60]

Has anyone heard of or used a product called "Marvel Mystery Oil"?
A couple of the mechanics I work with say they've tried it in their cars and they noticed an improvement in their gas mileage.
One guy has a gas powered VW Golf and he says he now gets 35mpg as opposed to 30mpg before using the stuff.
Here's a quote from their web site.

Marvel Diesel Supplement not only increases fuel economy by 8 percent and keeps fuel injectors clean and lubricated, it also improves the cold flow properties of ultra low sulfur diesel to prevent gelling and improve vehicle performance in cold weather. Adding Marvel Diesel Supplement can decrease diesel fuels cold flow point from -5 grade to -40 grade

::Marvel Mystery Oil::

Any input...?

[cody c]

I like the name of it! But it sounds like snake oil to me.

[PressOn]

Anecdotal but I've had good luck with it. I had a ticky subaru engine (common for subaru's) and if I put ~1 cup of MMO in the oil shortly before an oil change, there were no more ticks for the next 3000 miles. If I forgot to add it, the ticky came back. I put 200k on that engine and it sounded great the day I sold it.

I did not like to add to the fuel though. On two occasions, when I did, one of the O2 sensors gave me an error. It took a couple tanks of high octane fuel to eventually clear it.

I do have to agree that based on the name alone, it does sound like snake oil and did nothing to convince me to use it. I used it per the recomendation of an aircraft mechanic who worked on my father's plane.

Jeff

[Joe Egolf]

Marvel mystery oil has been around for years .I used it years ago but quit using it when an engineer friend told me it was a cutting oil ,ie wear. Now Marvel diesel supplement is new to me??

[rchalmers3]

Hopefully they haven't redesigned the packaging. The ole timey style really fit the snake oil image!

And just like any additive, you will find people reporting anything from wild improvements to negligible results.

Well engineered snake oil dosen't hurt anything! It's supposed to be rather inert so you will keep buying and recommending the stuff!

Rick

[Diesel42]

It's been around for ever. Old farmers swear by it.

[lshobie]

A bunch of pilots and a/c mechanics used to use it in the older aircraft at my airport, they swore by it - but like any other additive who knows.

Louis

[My wife said no FJ!]

Originally Posted by PressOn

Anecdotal but I've had good luck with it. I had a ticky subaru engine (common for subaru's) and if I put ~1 cup of MMO in the oil shortly before an oil change, there were no more ticks for the next 3000 miles. If I forgot to add it, the ticky came back. I put 200k on that engine and it sounded great the day I sold it.

I did not like to add to the fuel though. On two occasions, when I did, one of the O2 sensors gave me an error. It took a couple tanks of high octane fuel to eventually clear it.

I do have to agree that based on the name alone, it does sound like snake oil and did nothing to convince me to use it. I used it per the recomendation of an aircraft mechanic who worked on my father's plane.

Jeff

So...you simply added 1 cup right into the existing oil...you say just before an oil change...how 'just before'? 500 miles? One good two hour drive? I heard about this with other products, and the key was to get the engine real warm/hot to let the oil/aditive work into the engine...would this be what you did?

Never done this myself, but it sounds interesting...anyone know/have a down side to trying this out on a regular gas engine? What about a newer car like a camry or corolla...could these people get better mpg because their engines would work easier?

[JJS]

I put it in my air compressor once in a while. The top end is in rough shape.

[PressOn]

Originally Posted by My wife said no FJ!

So...you simply added 1 cup right into the existing oil...you say just before an oil change...how 'just before'? 500 miles? One good two hour drive? I heard about this with other products, and the key was to get the engine real warm/hot to let the oil/aditive work into the engine...would this be what you did?

Never done this myself, but it sounds interesting...anyone know/have a down side to trying this out on a regular gas engine? What about a newer car like a camry or corolla...could these people get better mpg because their engines would work easier?

I just added the MMO and drove roughly 10-20 miles and dumped the oil and filter. More than enough to warm everything up.

A little more information is my parents also had a ticky subaru. (Mine was a 95 legacy and they had an 03 outback) The same approach quieted theirs but it didn't last between oil changes. They'd get roughly 500 miles and the tick was back. Not sure what's so noisy in those boxer engines but it helped.... some more than others.

I kept close track of fuel economy on my subaru and I can say that the treatments didn't seem to have a significant effect.

Jeff

[My wife said no FJ!]

So if it helped for 500 miles, then why not leave the MMO in all the time?

[PressOn]

Originally Posted by My wife said no FJ!

So if it helped for 500 miles, then why not leave the MMO in all the time?

Never done it myself but that's what MMO recommends so give it a try.

The only thing that concerns me about leaving it in long term is the viscosity of MMO seems low compared to the oil. I have nothing to reference but I wondered about thinning the oil too much for long term use. Again, just intuition so I didn't feel like my parents car was a good test subject.

[liljlandon]

We sell quite abit of it, and all of the farmers swear by it. Considering we are a feedstore, thats pretty much all we sell to is farmers. We put a bottle in our chevy 1ton (454) every 2 tanks, and it does help in the intial start up. Sometimes you have to crank it 30 seconds two or three times before itll fire. With MMO it fires first crank. For about 2 tanks. then it cranks forever agian...

[cruiser user]

I had a 1950 Cessna 140 A with a continental engine designed for 80 octane Avgas which is no longer made. PO used 100 octane leaded Avgas . Result was sticking valves due to lead deposits around valve guides. My A&P mechanic pulled a plug on the bad cylinder ,stuck some rope thru the hole and cranked over the prop by hand. The rope in the cylinder compressed and freed the stuck valve then some MM oil went in the sump and and a quart in the gas tanks and the problem was solved. Engine ran happily from then on with a regular dose of Marvel .The stuff works and smells good too! Drink sparingly, too much loosens the bowels ! Happy landings!!!!

[spoof]

Agreed. No input on running MMO, but I've definitely used it to free stuck cylinders before. Works good for that in my experience. As an additive, well......

[Eric Winkworth]

I think it kind of sounds like sea foam... Which I think is the best thing to add to your oil before a change... I've been afriad to do it to my cruiser.... If all that carbon comes out, I may have some leak problems.



cheers

[RufusTheDufus]

I run MMO in the gas tank on my Yamaha Road Star (air cooled v-twin 1600cc). These engines are known for having sticky and loud valves. There are a few mechanics that participate in the Road Star Riders forum that swear by this stuff in these engines. I use an ounce per 4.5 gallon tank. Apparently it doesn't clean the carbon from the valves as well as Sea Foam does so I occasionally run an ounce of Sea Foam through the tank too.

I don't use it in any of my other vehicles.