Marvel Mystery OilMM14R-4PK - 1 Gallon (Pack of 4)

MMO is an old-school oil and solvent that can clean and loosen many aged and abused parts. I add it to the fuel of my cars, and feel a difference, although it could be imagined...Much better price here than in local stores, so although I generally prefer to support brick and mortar, sometimes value wins out :-)

Love it. Well worth having

Hope that using this in the cylinder of the mower that was flooded by hurricane Ian. Putting 3 ounces in the chamber weekly. Now on 3rd week. No results yet.

I've always wondered about Marvel Mystery Oil as I've seen reviews along with various YouTube videos about the benefits of this product. So I decided to give it a try. Make sure you follow the instructions on the label for the application your using it for! It doesn't take a lot, whether adding to your oil or your gasFirst I put some in my gas tank at the recommended amount (4 oz per 10 gallons). Most people do this 2 to 3 times to get the full benefits of the product. So a 16 oz bottle of Marvel Mystery Oil would treat 40 gallons of gas. It has improved the performance of my 2011 KIA Sorento 4 cylinder after using on 40 gallons and I'm going to change the spark plugs now. On my significant others 2002 Toyota SR5 4runner, we've had issues with 3 of the idiot lights always staying on, which I've read could be the O2 sensors. On the 3rd application (I used a bottle, 4 oz per 10 gallons, 4 times in a row) those lights went off and have stayed off for 3 months now! Did it clean out the O2 sensors? I'm going to say yes because they have been on for a full year!Then I added some to my KIA's 4 cylinder oil. You can add or replace 20% of your oil so if you use 5 quarts of oil, you could replace 1 quart of oil with Marvel Mystery Oil. I had changed my oil around 3,000 miles ago with full synthetic Castrol Edge along with using a high dollar synthetic oil filter. This synthetic oil has been so "clean and clear" that it was difficult to read the level on the dipstick. But it was like a 1/2 quart low. So I added 10 oz directly to the motor. 200 miles later, the oil went from almost being clear to black!! So it definitely was cleaning something. I drove it 300 more miles and then changed the oil and filter. I had read that you should add this product like 500 miles before your scheduled oil change and now I see why! My KIA is purring like a kitten and I'm getting 3 more miles per gallon on the highway (78 on the interstate).Finally, I had added some (4 oz) to a 1 gallon gas container for my lawn mower and the some to the 1 gallon mixture of gas/oil for my old Toro snowblower. The snowblower had been running rough and occasionally dying on me. By the 2nd time I refilled the Toro's gas tank, that 25 year old Toro was once again running like it did when I got it new! I'm serious here! Then this Spring (right now), it naturally was added to the lawn mower. I just got done mowing the yard for the 2nd time this year and it uses 1 tank of gas to get the entire yard done. When I went to start it up, it started on the first pull as usual. But a HUGE gray smoke cloud came out of the exhaust! And it's never done that before. But it's purring like a kitten too!I'm no mechanic but am rather handy. Just installed a new capacitor on the outside air conditioner as it wasn't cooling. And it solved the issue.Marvel Mystery Oil says it improves compression, power, & MPG, along with lubricating upper cylinder for smoother idling along with keeping engines clean from sludge. Based off my results or experiences. I would have to agree 100%. I'll keep adding a little to the gas now & then. But if I add to the oil, I will only due that like 200 miles before the next oil change. I recommend trying!!!

I was first introduced to Marvel Mystery oil for more than 5 years, and I have seen a better performance in my vehicles.

RC engine

After aircraft engines (both Continental & Lycoming ) get a lot of operating hours (around 1600 hrs. ) sometimes they begin to develop “morning sickness”. This is valve sticking. Usually the exhaust valve & guide. This product when used as directed - may save you from pulling the cylinder and reaming the valve guides. Expensive and fraught with problems. Good Luck

I want to believe that something is going on in the background, but I have yet to actually feel or see any differences. It has been about a month since my oil change and introducing this into my engine. I'm giving the product 3 stars as it hasn't had any adverse reactions, but I can't quantify yet any positives from adding it in. I'll do it again for the next oil change but that may be the last before I switch back to Lucas. My vehicle is a 2001 Mitsubishi Galant with 212k miles. Like I said, the engine runs relatively well and I've been pleased, but I'm not certain of the benefits, if any, at this point. Actually, the more I think about it, I have experienced a bit of a rougher idle and some slippage upon acceleration. I can't say if that is a result of the oil being thinned out by this fluid, or if it has cleaned it up so much that I'm now feeling it. I have not, however, used this in my gas tank. I have been using Lucas religiously at this point for the last 2 years. I doubt there will be much advantage from a gas additive at this point, but I will may try it.Overall, I suppose it may have some great properties when used as a fuel additive. I can't speak to any benefits when adding it to your oil (yet). I will use it in the next oil change and see if there are any improvements. I'll follow-up with an update after I have done that.*UPDATE* 6/8/16So, I am in need of another oil change and I have noticed some drastic changes since I first put this in. It's very clear to me that this product cleaned out some gunk in my engine. The results were not what I was expecting, instead of smoothing out my idle (which I think there has been some improvement there), it now burns off more oil. I am contributing that to the fact that it simply exposed the flaws in my seals. I don't mean this from a negative, destructive way, rather it cleaned it up so much that my failing seals are now actually failing instead of being gummed up. I now have some decisions to make as to how I'm going to fix the issue (some other fluid most likely). Until then, I believe I a done using Mystery Oil, although I am impressed with it's ability to clean out my engine. Actually quite pleased with the results, increased a star!

Won’t know for quite a while. Depends on how long my generator and snowmobile last compared to others.

I'm using it just in the gas tank and it's keeping my spark plugs clean and melting away the carbon in the engine.

Works well for rust removal on chrome

Use this with amazing results in everything I own with a motor.Use as directed and you will see!

I used it in my Dodge Caravan. I have noticed anything more or less