This is meant to be a general discussion on oil related topics, but I have a question regarding Marvel Magic Mystery Oil. Has anyone, aside from my grandpa - and other 70+ year-olds - used it with any success or failure?

I have read, in different diesel forums (not here) that if you have an old diesel, that hasn't been driven much, if you put around 20% MMO in the crank case, it'll loosen up the rings to help lessen blowbye. Truth? Fiction?

 

im 50 and used it in my younger days on v8 engines to quiet lifters and it worked...also filled stromburg side draft carberators on old jags with mmo..it was sold in all gas stations.

 

Not sure if it would help in the fuel or oil. I've used it with success to free-up old motors that have been sitting/ rusting. To tear them apart and getting them going again

 

Thanks, all, for the input!

 

I know they are forum sponsor, but what's everyone's opinion on Amsoil? My dad used it in his Duramax, and obviously it ran fine, but what about it compared to Mobil, or some other good brand?