Oil Additive, ZDDP Plus

Zinc Dialkyl Dithio Phosphate (ZDDP) is a critical anti-wear ingredient in engine oil. It's being phased out because the small amount that sneaks into combustion chambers reduces the service life of catalytic converters, which of course is not an issue with vintage cars. For modern roller-tappet engines, the reduction of ZDDP is not of grave concern, but for flat-tappet engines such as those fitted to Jaguars, it is of critical importance. ZDDPlus restores this anti-wear agent and ensures proper lubrication. Sold per 4-ounce bottle, which will treat 4-5 quarts of oil. Please note that ZDDPlus cannot be used in cars equipped with catalytic converters.