To help prevent damage to catalytic converters the EPA has mandated that zinc levels be reduced in motor oils. Zinc is an important high-pressure lubricant that is needed whenever two metal surfaces slide against each other. This is the case where the lifter slides over the camshaft on the A-Series engine.
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Please Note: Due to shipping restrictions, this item can only be shipped to addresses within the United States.
From the manufacturer:
After 70+ years, the EPA mandated that all domestic oil producers remove ZDDP (Zinc Dialkyl Dithio Phosphate) from all conventional and synthetic motor oils. If your engine was designed before 1989 the non-roller lifters require ZDDP to avoid premature deterioration. ZDDP also alters bearing and journal surface characteristics to prevent metal to metal contact. Under extereme conditions like a high performance motor, ZDDP reduces the tendancy of parts to scuff or gall under heavy loads. Simply add ZDDP Oil Additive to every 4-6 quart oil change and your motor will be protected. Packaged in 4 ounce bottles.