Hello! New guy here.

Will MMO work as a lead substitute in older vehicles?

thanks!

While Marvel Mystery Oil provides additional lubrication, it does not operate by the mechanisn as does a lead substitute.  When we had leaded gasoline, the tetraethyl lead besides being an octane increaser, it also formed a lead oxide coating when combusted.  This lead oxide coating was constantly formed and worn away to prevent metal-to-metal contact and thus reduce wear. 

A true lead substitute contains either a sodium or potassium additive.  When combusted in the engine, either a sodium or potassium oxide coating is formed and behaves the same way as the lead oxide coating.  We suggest that for a true lead substitute, use our sister company’s CD-2 Concentrate Lead Substitute.  This product is available at Wal-Mart and other automotive stores.

Thanks, I did just pick up some of the CD lead substitute. Can I assume that I can put both MMO and lead substitute in the same tankful? or should I alternate them?

Both products, CD-2 Concentrated Lead Substitute and Marvel Mystery Oil are completely compatible with each other.  Therefore, they can and should be used together.

Thanks Rich!