Premise: virtually all of the currently available oils with the latest SM or CJ-4 designations have zinc and phosphorus levels at or below 1,000 ppm. * The 1977 SAE paper Cam and Lifter Wear as Affected by Engine Oil ZDDP Concentration and Type written by two GM Engineers provides plenty of data to support the assertion that 1200 PPM is knee in the curve of wear rate vs ZDDP concentration for flat tappet engines. Was neglected, Now Re-born, We hope so
Statement: Was forgotten, Now Re-born, We hope so
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