Mixing motor oil to reach the right ZDDP level for classic cars

“For an older, flat tappet, performance motor with inherent cam wear issues is there any benefit to mixing high ZDDP Mobil 1 Racing™ 4T 10W-40 to Mobil 1™ High Mileage 0W-30 oil? The 15W-50 creates TOO MUCH oil pressure. It would be nice if you had a product for 'Classic' cars, high ZDDP, 0W-30 and 0W-40. I have used nothing but Mobil 1™ oil for 15+ years.”

Bill McCauley, Tallmadge, Ohio


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.

Not finding the answer to a question like yours?