Anyone use Marvel Mystery Oil in their fuel?

[marks737]

I've heard great things about Marvel Mystery Oil when you add it to the fuel at fill up. Improved performance, better mileage, better lube and protection for top end and injectors etc...Are there any negatives to using this stuff?

 

[Ka1oxd]

That is real old school. I also use it when I top off my oil near the end of the season. Run it for a few hours then change the oil.

 

[Larry]

I also use it when I lay up the boat for the Winter, I put a good dose of it in the fuel and run it a while as part of my winterizing process. I have never heard anyone say anything negative about using it even in EFI motors.

 

[LawyerMan]

Is it safe to use at every fill up?

 

[dpmulvey]

Is it safe to use at every fill up?

I use MMO and Stabil Marine in the recommended doses at every fillup and double up at winterization. It could just be something in my head (or lack thereof) but I have issues with alcohol laden fuel sitting for a length of time in the top end of my engines.

I have never had an issue starting in the spring. or during the season.

 

[Ka1oxd]

Yes, and it is good for that too. I do run Startron in my gas to keep the water from collecting. It seems to keep the engine running smooth.

 

[Bt Doctur]

400,000 miles in my tow vehicle count?

 

[Paladin]

I "believe in" Slick 50 with your oil chnages..