View Full Version : Marvel Mystery Oil

05-15-2013, 03:32 PM
I've used Marvel Mystery Oil for 30 years in various engines with good results. Detroit Diesel says no additives but I know many others who swear by this stuff and run it in their prevosts and bus conversions.
Has anyone used the product, and if so what are the results.


05-15-2013, 03:46 PM

I always add MMO at every oil change,along with 1 bottle of STP with no problems.


05-15-2013, 04:50 PM
I have a good friend who is an OTR owner operator. He has been using Marvel Mystery Oil for over 20 years & swears by it.

05-16-2013, 12:37 AM
The perspective I'm always interested in is what the major trucking companies are doing with their trucks. If Marvel Mystery Oil is making an improvement that exceeds its costs I assume the trucking companies would mandate its use as standard for their operations. Since the makers of MMO would find it very advantageous to have major trucking companies on board and since I've not heard a peep about that I'm guessing no major trucking company is regularly using it. If I am wrong I certainly would like to be corrected so I can start using the stuff and saving myself some money.

Everything I know just ain't so

Newell Attack
05-16-2013, 05:10 PM
How much MMO do you add to the crankcase on oil changes and is it really worth the added expense?