Success with Marvel Mystery Oil
 

'97 Honda Civic HX, 250K miles, head rebuild a year ago, stock engine, many aero and electrical mods.

I've been using Marvel Mystery Oil (MMO) in the Civic since January 17,2012. For this car, it's a winner.

The Civic HX offers lean burn and one of my gauges lets me know when I've achieved it. LB seems to net me about a 10% mpg increase, maybe 15%. Lean burn state was nearly always limited to 61 mph and above when in 5th gear, though drivers of other HX's told me they had lean burn below 50 mph. What hypermiler wants to spend all their time above 61 mph to save fuel?? But I could only get low speed lean burn for a couple miles or so at the start of a highway trip, and that was all.

Anyway, at one oil change I added 1/2 the suggested concentration of MMO to the crankcase (suggested = 20% of sump capacity) and 1/2 the recommended concentration to the tank (suggested = 4 oz/10 gal). Ta-daaahh! Lean burn was there, down to about 46 mph. Since then, I've upped the concentration of fuel tank MMO to the recommended amount, 4 oz/10 gal. Nice markings on the 1 qt bottle help you get it right.

The MMO in the tank is definitely needed. The first time I filled up and did NOT add MMO to the tank, low speed lean burn went away. Pulled off road, added a few ounces, and lean burn came back. Thankfully circulating fuel pump systems help mix up whatever you may have in your tank.

I don't know whether the MMO in the oil sump is helping this engine any, but I'm continuing with MMO there at 10%.

True that MMO costs something like $20/gallon, bought in quart sizes. However per fillup it's only about $0.60 or so, not even worth thinking about, IMHO.

I've always been a fan of MMO, but never had any "proof" of its effectiveness. I've been told that it is basically hydraulic oil.

i want to hear more...

mcrews -

Me too.

CarloSW2

I am curious as to why this additive is working?

Did it clean the injectors allowing for better performance at lower RPM's? Have you tried not using the MMO in a couple of tanks to see if the effects are lasting?

Some interesting information on various additive in diesel fuel including MMO. This only relates to wear and not fuel economy.

http://www.johnfjensen.com/Diesel_fu...itive_test.pdf

...what does the MSDS for MMO say it contains?

3 . COMPOSITION / INFORMATION ON INGREDIENTS.
Hazardous ingredients

Dichlorobenzene ---------- 0 - 5%
Fine White Mineral Oil -- 70 - 100%
Mineral Spirits ------------ 20 - 30%

Turtlewax msds

Looks like it's cleaned the injectors?

It doesnt seem to be clean injectors causing lean burn. Notice he said he filled up and lean burn went away, he pulled over and added MMO to the fuel and lean burn came back. That seems to indicate it does something to the fuel mix and maybe sets off a sensor? I wouldnt think the injector clean/dirty state would change that quickly.

So, Bruce would you try a tank (or partial tank, given the price) of high octane fuel without adding MMO to see if its the octane that sets it off?

Any other ideas?

Maybe the injectors like extra lubrication.

One of MMO's benefits is removing carbon. I mainly use it on old small engine in the crank and fuel to prevent carbon build-up. That may be where your benefits come from. You probably can start using less with every tank unto you have a maintenance amount.

Other ways to remove carbon is too clean with steam or an Italian tune up (High RPM WOT driving).

I recommend you not using it in your oil anymore due to the mineral spirits.
It is good for an engine flush, but not for continuous loading.

Solvents like mineral spirits will break down the oil film, and it doesn't take much.
It has the effect of thinning the oil. On high mile engines it also makes the blowby more volatile. Those two effects can/will increase fuel mileage, but it's not worth the expense of causing bearing or lifter/follower failure.

I couldn't say what concentration % of mineral spirits is enough to cause a failure, but I'm sure it's different for different engines and situations.
I have used mineral spirits on many occasions in several different ways.
You can put it in a sprayer and directly spray combustion chambers and pistons through the spark-plug hole. This will clean and often free-up piston rings that have either seized or have limited travel due to build-up.
Putting it in the engine oil is also a good way to clean the engine internally, but I only let the engine run at idle un-loaded, then change the oil.

I have added it to fuel on several vehicles as a cleaner for carburetors, TBI injectors, or MPFI injectors and fuel systems. It works well, but often has an effect similar to lowering of fuel octane, and that does improve mileage in many situations where the engine isn't heavily loaded.
I do not run it continuously in fuel so I don't have reliable mileage data.
In the vehicles that it improved the mileage in, Acetone has worked better, especially in cold conditions. For both additives the positive effect seems to be in proportion to how many miles are on the engine.
For example I could put some mineral spirits or Acetone in a brand new MPFI vehicle and get no significant measurable effect. On a vehicle with 200,000 miles the effects are very noticeable and easily measured.
I have test data for the Acetone, but like I said I haven't used mineral spirits or MMO on a continuous basis in order to collect mileage data. I buy the mineral spirits in the large metal containers from Lowes, and just use it as a cleaner.

*Mineral Spirits WILL dissolve lower grades of rubber over time. Acetone will do it even faster and has a wider range of materials that it will dissolve.

That is very interesting about the lean-burn mode and the sensitivity to the additive. Good discovery!

Anyone else try TC-W3 oil instead?
Been testing

I figured I'd give it a shot, but haven't used it long enough to notice anything.

I have used TCW3 in my '95 Chevy truck with noticable results (been too long for specific % or even mpg gains but I got 19.5 mpg on my commute with some ecomodder tips and who remembers what else). I followed a thread on Full Size Chevy forum that got me going. It has been quite some time since I ran it in the truck. I don't commute with it anymore. In the Century, I just added the TCW3 last fillup So, results have yet to be determined.

too new, cannot post the link. The thread is titled "2 cycle oil in your gas" and has a link to the LS1 forum. ^ "Been testing"

-Scott

I love Marvel Mystery Oil, it smells good, has tons of uses and is always found lurking somewhere in my garage. Havnt used it on the Escort, usually use it in my older, more wore out vehicles or to coat the cylinder walls on any motors I might have out and apart etc.
Matt

Tried some MMO in Stratus, in 100k mile don't think I've ever put any kind of cleaner into the fuel(220k on car). Test is limited, but 2 tanks before MMO 36.2 & 36.9 mpg, next 2 tanks 32.6 & 34.9. Changed to E0 on this tank so should jump back up some. Next tank will be E0 and no MMO.

I got some $6.99 2stroke oil with TCW3 @ Canadian Tire and added the suggested 2 ounces per 10 gallons, and wow I noticed and immediate smoothness of my idle and throttle response was way smoother and way peppier.
Now to see if it helps in MPG.

I'm halfway through my second tank using TC-W3 (1oz/5gal). There appears to be a slight bump in mpg, but it's small enough to be lost in my typicial variation in mileage. The benefits are mostly cleaning and lubrication of fuel system components and top end of the motor, so I'll keep running it even if I see no recordable mpg gain.

Marvel Mystery Oil (MMO) is somewhat heavier than gasoline, and gradually sinks to the bottom of the tank where it is picked up and consumed. So the concentration in your tank decreases over time or distance.

• MMO: 25.6 g/fl ounce (I weighed a quart on a scale with 2g resolution + did the math to allow for the weight of the bottle)
• Gas: 21.26 g/fl ounce (from wikipedia), see the "Density" section.

I've had nearly equal success whether adding 2 oz or 4 oz per 10 gallons gas. 2 oz/10 gal isn't quite as good as 4 so I suspect 3 oz/10 gal might be fine.

This all started when I found tthe availability of lean burn decreases after about 250 miles or 5 gallons (at ~50 mpg). I suspected the MMO is sinking to the bottom and being sucked up by the pump faster than the gasoline. The recirculating fuel system helps keep it mixed but there's nothing like splashing in a fillup to mix it all up.

At the 5 gal mark I'll be adding some MMO to keep the concentration up. Not sure exactly the dose and whether I'll add fuel at the same time or not.

I have a cousin who works offshore as a mechanic. Every year he rebuilds giant 2 stroke diesels. He says that they purchase MMO by the barrel to have shipped out there. I decided to try some for carburated lawnmower that "hunts" (rpm up and down). My engineer father in law just said some small engines do that. Well, mmo cured it. I have purchased more and am putting it only in my fuel.

I think the physical problem in my HX is in the EGR passages, and that Marvel Mystery Oil cleans up just enough crud to allow some flow there. From photos the EGR passages look to be about 1/8 inch diameter channels machined into a casting below the fuel injector rail. (See this post: How to Clean EGR Ports / Passages - Honda Civic Forum. And you can google for more writeups, youtubes etc.)

Somewhere I read the HX opens the EGR valve during lean burn; clogged passages would prevent the "wanted" flow of exhaust gas back to the intake system. I've occasionally had CEL stating insufficient EGR flow, CELs not helped by cleaning and later replacing the EGR valve.

I know, really I should clean the EGR passages but I'm not too much of a mechanic and don't relish the thought of taking apart all that stuff including the well-sealed fuel system components. One of these days in warmer weather I might get up the nerve and time to do it.

Bruce,

Seafoam produces serious fumes when burned. BUT it almost melts carbon build up. You might try dripping straight Seafoam into the egr channel if you can get to it. Let it sit for a while. I may open them up without taking the engine apart. I have used in several engines with good results.

I'm not doubting your belief in it or your claimed success with it. But I am skeptical enough to question what its components are. For anyone else who is interested, this discussion might be of interest: click here.

Thyme, no worries man, I have never researched what was in it, I just used it. I dont use it everytime I fill up.

My current car (82 Oldsmobile w/307) had sat for 10 years unused. I used the Seafoam Trans treatment in a flush and filter change and Seafoam in 2 oil changes. But I dont put it in and leave it. I added it and drove for a few hours, it makes the oil really dark really fast. I had a slight lifter tick, its gone. I have no proof but I am thinking it helped loosened up the varnish that was plugging the lifter so it can function correctly. I also dont know what solvents like these will do to the seals long term. I do know when you pour it in the carb it cleans the carbon build up visibley.

I have seen where people use a vacuum line to introduce it to engine and the shut it off to sit and then the impressive clouds of smoke. I have never done that. I did use a concentrated amount in a '46 Farmall Tractor, the fumes about killed me! But it ran better after the gas/Seafoam treatment.

I dont know if it will help the egr passage or not, its the only thing I can offer that I have experience with. Its like all snake oil treatments, use with skeptism. :D

I'm not worried, just curious. I found some interesting information on SeaFoam and am opening it as a new thread. (click here)

I seafoamed this car 2-3 times already, didn't help the lean burn problem. You can see the ick being blown out the tailpipe though!

Currently running 2.5 oz Marvel Mystery Oil (MMO) per 10 gallons gas. I'm using one of these to easily measure fractions of an ounce of MMO at the pump. Search on "Adjustable Measuring Cup" on Amazon or google etc.

http://ecx.images-amazon.com/images/...jL._SY355_.jpg