From site; Answer Mobil 1™ FS 0W-40 oil already contains a higher level of ZDDP (1,000 ppm) that could benefit your flat tappet engine. We also have a Mobil 1™ High Mileage 10W-40 (1,000 ppm); see the Mobil 1™ Product Guide listing the phosphorous levels for all Mobil 1™ synthetic motor oils.