one thing i failed to mention was to obtain that kind of milage, i was using mobile synthetic oil. In fact I still use it in the cummins I currently have. Also, there was very little idle time on it. We wanted the truck to get a year or two out of it because of the sleeper,genset, and the box. We would then pull them off and drop them on a new chassis. Much cheaper and yes we have reservations on the engine but at 50,000, we are hoping to get an additional 100 maybe two out of it. Of course we are still debating. Thanks for all of your input.