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Presence of Zinc in Engine Oils
Does Mobil Delvac have zinc in the oil? A lot of racers are using Shell to break in their cams in HP engines due to the zinc in the oil. It works the best. I think most oils for non-gas cars have zinc in the oil to help something?
-- Jeff Paquette, Raymond, NH
All engine oils have an additive called ZDDP (Zinc DialkylDithioPhosphate) for wear protection. In general, heavy duty engine oils (truck oils like Mobil Delvac™) have a higher level of ZDDP. Automotive engine oils generally have a lower level of ZDDP to protect catalytic systems. For details on phosphorous levels in Mobil 1™ motor oils, see a related question and its answer.