It's best to buy oil with the right amount of zinc in it rather than add any additive. There are a couple of oil testing sites that report that oil additives do not always have the intended affect. Apparently, sometimes additives clash with the oil and actually lowers the total zinc.

Nowadays, it seems no one recommends any additive for all oils.....except the additive dealer. Some do help in some oils, some times. But it is a real challenge to sort it all out.

Just buy the right oil. And I like the VR-1, too. It's what I run in my flat tappet Hemi.