Marvel Mystery Oil Original Motor Treatment, Engine Oil & Fuel Treatment Additive, Cleans and Lubricates Fuel System, Prevents Leaks, Improves Engine Performance and Fuel Economy, 32 oz. (Pack of 2)

Great mystery oil for maintaining vintage cars! Use as recommended by gear heads.

Just what I needed

I use Marvel Mystery Oil in all my engines ! It is great for small engines burning Ethanol fuels , Ethanol draws moister which causes corrosion , Marvel in fuel coats internal carb and protects it ! I swear by it , well worth cost ! Great price on Amazon and 2 day delivery being a prime member is great !

This stuff is amazing! I used it to clean out the oil system on a 1978 Corvette that had been sitting since 1988. A few treatments and heat cycles later the original 350 is humming with clean oil.

Marvel Mystery Oil Diesel Treatment is like a magic potion for your diesel engine, and it may just have you singing its praises all the way to the gas station! Designed to enhance performance, this treatment works wonders in improving fuel efficiency, potentially increasing your gas mileage like a turbocharged fairy godmother. Just pour it in, and let the magic happen as it cleans and lubricates your fuel system, reducing carbon build-up and ensuring your engine runs smoother than ever. Users often report feeling a noticeable difference in their vehicle's performance, with some even claiming to have achieved higher miles per gallon. It’s almost like finding an extra set of wheels in your trunk—unexpected but definitely welcomed! Plus, it’s suitable for all types of diesel engines, making it a versatile addition to any mechanic's toolkit or a weekend warrior’s garage. So, if you're looking to stretch your fuel dollar and keep your engine happy, give Marvel Mystery Oil Diesel Treatment a try. Who knew that adding a little mystery to your fuel could lead to such a fantastic transformation? Buckle up, because better gas mileage is just a bottle away!

I've been working on restoring a 1984 Honda spree from death, and it has been sitting with a half full tank for sometime so I needed some way to clear my lines and see if the motor was still worth the time. Luckily with just a few splashes and a little cleaning I got the motor to start idling the next day.

Very good oil to mix in gas to used in small tractors and lawnmower. Good value and helps engine to function very well and keep spark plugs cylinder clean.

This stuff works, made my old lawn mower run smooth and works like it did when it was brand new .. highly recommend this product

Helped unseize a snowmobile engine

The product seemed to work as described. Very quick delivery as well..

way too expensive, doesn't seem to make any difference but I still use just in case. UPDATE , Luckily i was able to return.