Flatbed 80,000 lbs a load. 2500 hundred miles a week and 2 gallons of Rotela a week. No oil leaks and not excessive blow by. No signs of oil burning out the stack. Oil Pressure good Oil change....... Because the old head driver begged me to went to Delo 400 and added a Gallon of Lucus oil syrup which I have never used before. Now truck uses 2 quarts in 2500 miles which is most acceptable. Truck has about 800,000 miles so I'm thinking valve guides maybe. Not going to go into it now. It runs to good to do that. What does the board think? I have heard complaints in the past about Rotella and high oil usage but I cannot find anything on the web about it anywhere. These complainers were not on a board of any kind.