Marvel Mystery Oil

[freesaints]

Any thoughts on using MMM as fuel/oil additive? I have an'87 930 with 147k miles. Not trying to fix anything, just thoughts around preventative benefits.

[gled49]

Guys in AZ where only ethanol fuel is available, are putting MMO in their CIS cars gas tanks to help preserve the fuel systems. Not sure of the ratio. The cars don’t smoke, maybe a few OZ’s per tank.

[Matt Monson]

Only thing I’ve ever used it for is slowly breaking loose a seized old engine.

[RS America]

Was the Car Originally designed for Leaded Fuel? Unleaded Fuel can cause Injector failures. I had a 914 with stock fuel injection, just kept losing injectors.

Started using Marvel Mystery Oil, Never had another injector failure.
the ratio is 1 ounce per 2.5 gallons.

[fanaudical]

MMO might be "snake oil", but I'm a believer.

I had an old Audi with CIS and it behaved much better with a little MMO in the fuel. I add ~4oz per half tank fill-up to my '75 with 2.7 and CIS and it does seem to run better when it's there vs when it's not.

My dad and my uncle each had Mopar big blocks when I was a kid; they had some arrangement that fed metered MMO directly into the fuel from a separate reservoir. You could tell when the reservoirs were empty because both seeming to have a little "ting" at idle without the MMO.

And as Matt mentions - it's great for freeing up stuff that's sat around for a while.

[porsche930dude]

fuel is very dry now with no oils in it to keep things lubed like it once was so any oily substance will surely help the valves and top end and fuel injection stay happy. My old blazer with 350 burned alot of oil like a quart every 500 i put mmo in the oil and it fixed it after that burned a quart every 2k so it freed up the rings or swelled up the valve seals i dont know but it worked for me

[gled49]

Follow up to post #2, 4OZ MMO to 10 gallons.

[tributeventures]

I have used MMO for years for many purposes. Lubrication, fuel additive ( really good for Detroit 2 cycle engineS) a cleaner polish on boat hardware. I’ve heard in the Bahamas the natives have a drink with it. You can’t go wrong with MMO.

[Larmo63]

I use it in my Porsches and my old VW bug.

4 oz to ten gallons is my ratio too.

[smadsen]

I think Marvel Mystery Oil came into accepted use in World War II mostly by airplane mechanics in the field. Fuels had become much more complex with differing amounts of things like toluene, xylene, benzene, tetraethyllead, and Lord knows what other volatile, aromatic poisons engineer could come up with. The demon tweaks made possible by more volatile fuel almost doubled the h.p. generated by aircraft of the day. It was pretty toxic stuff and tended to gum up carburetors, necessitating periodic maintenance. Mechanics found by adding MMO to the fuel, the carbs required less maintenance (read disassembly & cleaning).

Same thing with gunk & sludge build-up in the crankcase with old non-detergent oils MMO seemed to keep things cleaner, or at least kept the crud up in suspension until the oil change.

Now-a-days fuels are so clean, and motor oils are so good, it kind of precludes the use of additives. That said, it's always nice to feel like you're doing something simple and proactive to help the car run better.

And the stuff smells very automotive when mixed with motor oil, gasoline, and 50 year old leather seat covers. I recommend a little dab behind the ears for date nights.

[H-viken]

On a similar note I was told a little bit of two-stroke oil in the tank will be good for our old engines. So makes sense MMO works

[t6dpilot]

Love MMO, I even shave with it. JK... I put 4oz for every 10 gallons of 100LL that I put in to feed the Pratt & Whitney R985. Every other tankful.

[Reiver]

...and it's a dessert topping too!

[Kraftwerk]

Interesting...I used tp dump copious amounts into my 914 gas tank and the Honda 400F fuel tank,
The SC gets a 'glurp' every once in a great while, more out of habit than anything, it has a minty fresh wintergreen scent I always liked, not sure how the car feels about it.

The H.Q. used to be in Port Chester NY (?) very close to the Lifesavers factory.. Suppose they could've been sharing ingredients?

"Marvel Mystery Oil - Honestly So"

[MrBonus]

I've used a few ounces at every fill up in all my carbureted cars. I don't know if it makes any difference but certainly hasn't hurt anything to my knowledge.

I've always understood it that ethanol attacks various rubber and seals in the fuel system and Marvel supposedly combats that. Of course, this is the same claim made by every other fuel additive so maybe I'm just being sold a feel good product.

[freesaints]

All great stuff. Anyone add it to their oil when doing an oil change? I'm about due for one and wondering if adding some would help (or at least not hurt).

[fanaudical]

My dad would put a quart of MMO into the crankcase of motors the weekend before doing an oil change to clean things out. That was back when everything was dino oil. I don't think I'd mix it with anything synthetic or semi-synthetic today. Today's oils are so much better than 30 years ago - no sure you need additives.

[911obgyn]

I am not sure the VR1 20 50w has all the additives that clean, so i put some mmo in and drive a good bit before oil changes. I may change to the mobile 1 15w50 and not do that. Is this an oil thread? It says oil in it!

[jjeffries]

I was first introduced to MMO when I moved to the USA at age 15 (forty years ago) and bought a tired MG Midget. I haven’t used it in years, although I infer no negativity with that statement. I have an 82 SC with CIS (which I admire/enjoy) and a year or so ago I asked K-Jet guru Tony, aka boyt911sc if I should be adding any MMO or 2-stroke oil to my gasoline to help, lubricate or preserve my CIS system’s components. Tony routinely rebuilds and recalibrates these items and said he saw no need. So, I didn’t, but not being able to help myself I still add Techron once or twice a year. Assuming your car is in good mechanical condition, both in fuel/induction and engine mechanical (oil lubricated) systems, I think additives are unnecessary; driving the damn thing is what keeps it healthy. But I’m not denigrating MMO, it does smell good and perhaps is most effective as a placebo. And if I bought a 1915 Stutz Bearcat I’d certainly keep some on hand.

John

[Coblue]

I tend to think that the fuels of yesteryear are superior to the fuels of today. You could get high-octane no-lead ( or low-lead, really) for the same price as regular. Ethyl and Methyl.
As to MMO, I have used it as a two-stroke oil, and as an additive to help reduce 'tapping' at idle in four-strokers.