MMO corrosion prevention

[wings&wheels]

I've stayed out of the MMO discussion...until now. I use it in fuel only and only on my gasoline fueled classics...not the airplane, though a number of my friends with older design or lower compression engines do.

Many years ago when I was first getting into the car habit, the local British car guru swore by MMO as a way to delay or minimize internal corrosion in metal fuel tanks, above the 'water line', when cars are stored. I've seen several TR's and other old cars with this issue, but I also grew up near water w/ higher humidity (of note; near water d/n necessarily equate to nice...). His theory was that the sloshing of MMO treated fuel would leave a slightly more protective film than fuel alone. I saw the logic in his theory, but I don't know how effective it actually is, but for the minimal cost and effort, I use it.

Thoughts?

 

[Donald]

Are these classic cars getting E10 fuel?

 

[wings&wheels]

Originally Posted by Donald
Are these classic cars getting E10 fuel?


Yes, no choice around here, except for the occasional shot of 100LL....

 

[BMWTurboDzl]

Aren't a majority of storage tanks made of a woven glass composite? In any case you can test it out by placing MMO on a piece of metal and submerging it. If the MMO remains adhered to the metal then he might be correct.

 

[wings&wheels]

Originally Posted by BMWTurboDzl
Aren't a majority of storage tanks made of a woven glass composite? In any case if you want to test his theory just dip a piece of metal in MMO and submerge it in a water. After a few days take a look to see this light oil product is still adhered to the metal or if it is floating on top of the water.


Fuel storage tanks, probably. This is referring the space above the fuel level in a stored vintage car.

I suppose I could spray just fuel and the mixture on two metal strips and hang them in my barn....

 

[andyd]

Anecdotal evidence of the efficacy of MMO. The 528e tanks had a drain plug. If any of your cars has one ,you could install a petcock. Use it to drain off water. Other than that stabilize the gas and fill it to the neck after every use. Use MMO as directed in the fuel. I'm totally involved in the "mystery" in MMO. Gas engines seem to like it . It has a nice purple color and smells good.. It is cheap and at worst is harmless. I'm hoping it keeps varnish from forming in the small passages of my OPE carbs. It seems to. It does have a butt dyno effect. I dosed a fill up on Marina's 528e . Didn't tell her. She noticed that the car had more zip. That is as close to a blind test as I care to get. Another anecdote. My Willys' fuel pump died, A buddy gave me one of his spares. He told me that it had been on the shelf for ages. I took the diaphragm out carefully. It was intact, but dried and brittle. I soaked it in a saucer of MMO over night and the fuel pump worked 'til the end.

 

[expat]

It would be easy to test the idea with a clean strip of steel.

I like to fill the tank before winter storage so as not to leave room for condensation.

I DO use MMO injected into the cylinders at the start of storage to prevent rust, prevent sticking piston rings and hopefully still be there as an UCL in the spring.

 

[Yah-Tah-Hey]

The only mystery about MMO is why it is revered by some individuals. Nothing but a light oil with a distinct smell. Overpriced and overrated.

 

[DGXR]

There is some logic in using MMO to prevent rust/corrosion in metal fuel tanks, especially those that are older and/or sit for long periods (storage tanks or seldom-used vehicles). In modern plastic tanks, obviously corrosion is not a concern although water can still form condensation. Ethanol blend fuels will help remove water in frequently used vehicles because ethanol absorbs small amounts water. I don't think MMO helps remove water but it does clean and lubricate, and is often used as fogging oil.

 

[kschachn]

Originally Posted by DGXR
I don't think MMO helps remove water but it does clean and lubricate, and is often used as fogging oil.

What does it clean and where have you seen evidence it does? I've looked on their website, and although it mentions "cleaning for engines and fuel systems" it doesn't provide any evidence whatsoever it does so.

Also, what needs lubricating?

 

[DGXR]

Originally Posted by kschachn
What does it clean and where have you seen evidence it does? I've looked on their website, and although it mentions "cleaning for engines and fuel systems" it doesn't provide any evidence whatsoever it does so.

When adding MMO to engine oil, I cannot tell you the specific parts that are being cleaned, just internal engine parts. Many times I have seen engine oil turn dark more quickly when MMO is added. This appears to be evidence of cleaning, or maybe it's just me? (Previously, the oil would take noticeably longer to turn dark.) This evidence of cleaning does not happen every time with every engine, but in some engines that haven't seen regular maintenance, this is pretty common for the oil to turn dark more quickly with MMO added.

Originally Posted by kschachn
Also, what needs lubricating?

When adding MMO to fuel... the fuel pumps, fuel injectors and upper cylinders benefit from the additional lubrication. Many other fuel additives (besides MMO) are designed to provide upper cylinder lubrication where the ring pressures are highest. Modern ethanol blended fuels are "dry," and while they have good detergent additives, the lubricity quality of pump fuels has really dropped off.

I don't expect my vehicles to last forever, and I don't use oil or fuel additives all the time, but I am willing to drop a few bucks here and there to help them along.
Dad was a commercial aircraft mechanic for 40 years -- he taught me that maintenance is cheaper than repair, and there is evidence that certain products help equipment to last longer.

 

[wings&wheels]

I think I see an opportunity for a test with two bare metal strips hung in the shed; one coated with a fuel/mmo mix and one bare. will post results...more to come.

 

[kschachn]

Originally Posted by DGXR
When adding MMO to fuel... the fuel pumps, fuel injectors and upper cylinders benefit from the additional lubrication. Many other fuel additives (besides MMO) are designed to provide upper cylinder lubrication where the ring pressures are highest. Modern ethanol blended fuels are "dry," and while they have good detergent additives, the lubricity quality of pump fuels has really dropped off.

Nah, those things don't need lubrication nor do they get it from the additive or the fuel. But if it makes you feel better then that's what's important I guess.

 

[red7404]

i started useing TC-W3. at 1 OZ to 5 gal. the only thing is i cant know how much good it does.

 

[demarpaint]

Originally Posted by wings&wheels
I think I see an opportunity for a test with two bare metal strips hung in the shed; one coated with a fuel/mmo mix and one bare. will post results...more to come.

Interesting, keep in mind a vehicle that is driven has the fuel sloshing around re-coating everything as you drive.

 

[Nickdfresh]

Originally Posted by Yah-Tah-Hey
Overpriced and overrated.


Debatable, but it's a fair point. But a qt. is less than $4 at Wally and last 5-7 tanks of fuel for most people. Some of the Youtube mechanics that test this stuff have said it seems to have at least some limited effect...

Quote
The only mystery about MMO is why it is revered by some individuals. Nothing but a light oil with a distinct smell.


That's not true, it reportedly contains TCP, which isn't just a light oil but is a fairly potent solvent that is capable of dissolving carbon and other deposits. It's merits are debatable, and use is even questionable given that TCP is a carcinogen and anyone that's had to deal with its cleanup at dozens of environment sites knows this. I doubt its concentration is high nor is it harmful being burned with gasoline.....

 

[MolaKule]

From 2014:

Quote
While not a PCMO or HDD Oil, here is the latest analysis:


Marvel Mystery Oil - Analysis by University lab

(Any element with 2 ppm or lower is not reported)

Phos - 631 ppm [Added - used as a lead scavenger in leaded fuels]

Use: Anti-wear

Potassium � 60 ppm

USE: Buffer and weak detergent.

Viscosity � 2.3 cSt@100C, 7.9 cSt@40C

Comment: One very LV liquid! Due to light fraction Hydrocarbon Content.

Flash Point � 143F
TBN � 0.3
Glycol � 0.63
Oxidation � 10

Hydrocarbons:

Naphthenic Hydrocarbons
Use: Oil Carrier and weak Solvent

Mineral Spirits
Use: A Medium Solvent

Chlorinated Hydrocarbons of orthodichlorobenzene
Use: Strong solvent and decarbonizer


https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4664422/1


P.S., there no indications from the spectrographs of it containing any rust inhibitors or metal inhibitors.

 

[Rmay635703]

I had a failed 98 3.8 Buick
2 of the 6 cylinders had excessively low compression to the point they didn't fire much.
Car would barely start and stall every time I came to a stop

MMO allowed me to drive another 100,000 miles in that state because the car would run normally with its does

 

[kschachn]

Originally Posted by Rmay635703
I had a failed 98 3.8 Buick
2 of the 6 cylinders had excessively low compression to the point they didn't fire much.
Car would barely start and stall every time I came to a stop

MMO allowed me to drive another 100,000 miles in that state because the car would run normally with its does

That's amazing. You should post your experience to their testimonial (Reviews) site:

http://www.marvelmysteryoil.com/reviews/

Maybe you'll get a hat or something.

 

[Linctex]

Originally Posted by Yah-Tah-Hey
The only mystery about MMO is why it is revered by some individuals. Nothing but a light oil with a distinct smell. Overpriced and overrated.


Incorrect, sir.

There are in existence actual chemical analyses of the stuff available if you look for them.

It (used to?) have a phosphorus based anti-wear additive, and a cleaner/detergent of some kind.
I don't know how much the recipe has changed (if any) over the years.