>If you're going to add something to diesel for lubricity, why not use a good quality 2-cycle oil instead of Marvel or transmission fluid? In addition to the lubricity additives the refiners put in to ensure proper lubricity--- which many people say eliminates the need for aftermarket lubricity additives altogether--- there are also aftermarket additives that are made specifically for this purpose. Some of them are made and marketed by the oil companies themselves. On the advice of our diesel shop and people we know in the marine diesel industry, we have used a lubricity additive called Select3 since buying our boat in 1998. Select3 uses a mil-spec (for what that's worth) additive called Lubribor. Select3 is made by Hammonds, which is the same company that makes Biobor, the diesel fuel bug killer, which we also use. I don't know if the Select3 is helping or not. I do know that in the 12 years we've owned the boat they don't smoke any more than they did a few thousand hours ago (and that only at startup) and that the oil consumption--- less than a quart per engine per 100-150 hours) has remained unchanged since we bought the boat. But given my understanding of the Lehman 120's jerk injection system, lubricity is very important to the longevity of the Simms injection pump and the injectors and better more lubricity in these old engines than not enough (something that may not be true of a new-generation diesel, I don't know.) Other than Bob Smith at American Diesel, I have not heard any diesel mechanic or person associated professionally with the marine diesel industry (or the fuel industry) promote the idea of using Marvel Mystery Oil. Most of the marine diesel people have told me that using a lubricity additive in an engine like the FL120 is a good idea, but none of them other than Bob have ever recommended that MMO be that additive. ______________________________ C. Marin Faure GB36-403 (grp) "La Perouse" Bellingham, Washington