I have used it in both my diesels with good results. I use an ounce of additive for every three gallons of fuel. For the Deuce that's about 25 ounces, 12 for the 36 gallon fuel tank on the Dodge Cummins. Both start real well and alot less black smoke. As I understand, it has lubrication additives to make up for the low-sulpher fuel. I went to a bike store and got a "Ratio-Rite" cup to measure out the additive, a plastic cup graduated so I mix it correctly. I also use this same cup for my 2 stroke engines that don't have oil injection. The cup is a little more accuarte than the scale on the side of the bottle.