Motorcraft Diesel 15W40 has 1335ppm ZDDP,Rotella has been reduced to about 1100ppm,the Motorcraft is about $16 for a 5 quart jug at Autozone or Wal-Mart.Some will tell you Valvoline 20W50 Racing oil is a good bet,Royal Purple and some other brands have a "break-in oil" but they can be pricey.