I really hate getting involved in these types of conversations because People understandably get very territorial and the last thing, I want to do is offend anyone. I used to espouse my beliefs one of which to add zinc to your choice of motor oil, but I have changed that opinion based on not only this but many other engineering articles over the last few years. Zinc is an important part of an additive package but only one of many other just as as important anti wear factors. As a former mechanic I felt kind of stupid for never even considering that by adding a compound to a base oil with an already extensive balanced additive package I could actually be degrading it by chemical processes that can occur under load. My father was an old school mechanic and he taught me from a very young age that you did not need to add anything to motor oil if you were using the right quality oil, I guess I thought I knew better. I am no engineer but one thing I do know is to never trust any manufactures claims of how good their product is because if I did everybody's product would be the best there is.