Thread: MMO and Fuel Mileage

I have used MMO (Marvel Mystery Oil) for the last few years but never actually measured and just poured a little in my tank, filled and drove. The last four tanks I measured and wrote down my results.

4th tank ago I used a commercial cetaine boost and lubricant. 14.3 MPG recommend amount.
3rd tank ago same product, doubled amount. 14.5 MPG
2nd tank ago MMO 2 oz per 10 gal. 15.3 MPG
Last tank 4 oz per 10 gal. 15.78 MPG

After that fill which I used 4 oz per 10 gal again the idle is higher. I don't know how that works but I am going to have to turn it down.

All the driving is city block to block lights, some blvds but no freeway. A daily commute of 10 miles each way and the wife driving. The fuel station is 2 miles away and pumps more diesel than any other station in the area and it is always fresh. Same pump each fill.

I used it for a while myself, until I realized that 2-stroke did the same thing more cheaply, it did seem to help mileage a little (this was in the Dodge), to me the more important factor is IP lubrication, this new ULSD is like water, smells like turpentine or paint thinner when you spill it!

My next test will be Johnson OMC brand 2 stroke oil. I will post it when I finish this tank. That will be next month at least.