I use either MMO or TCW3 with every fill up of my 1998 Chevy 6.5td. I use a full quart of either on an empty tank fill (less than a quarter tank). If it's a partial fill I guess at the amount. I can't tell a difference between the 2. I do it to help aid in lubricating the injector pump, 170k same pump so it can't be hurting. As far as a car or motorcycle, I've only used MMO.