It's a very confusing topic. One reason is there is so much bad info out there such as the ppm of zinc being an only determining factor. Such as " you need 1200 ppm of zinc". Really? What about calcium? Calcium and zinc fight each other. So an oil with 800 ppm of zinc can actually be a better oil than one with 1200 ppm if the detergent package, which calcium is a part of, is lower in the 800 ppm oil. There is also boron and friction modifiers that also play a role. Again there are different types of zinc. Break in oil has a type of short chain zinc molecule That bounds quickly which makes it great for break in when the cam and lifters are starting with nothing and that type of oil has very few if any detergents so the zinc stays in place. But it is short lived which is why it is only for break in. So what I am saying is do not get hung up a specific number for zinc when determining if an oil is good. It's only a small part of the story. Take into consideration there other additives that have been developed to take the place of zddp. For a stock engine, most off the shelf better quality oils will perform just fine. For a performance engine or you don't mind spending more money, use one of the oils such as Penn Grade, Driven Hot Rod or GP1, Amsoil, etc. Don't use additives!
