Engine oil

It basically boils down to if the oil you buy has the SAE medallion and that says SL or SM, you have no more zink than any other brand like 1Wild said. Also to add to confusion... things that say "Race" but have the medallion.. have no more zddp than any others. Federally mandated regardless of what the bottle says. Here's a link to the VR1 FAQ page. http://www.valvoline.com/faqs/motor-oil/racing-oil/

What I recommend is the "Not For Street" oils. If you've ever handled them them smell sort of like gear lube and feel much slicker than SM oils. They run about $48/6 bottles.

I'm sure there are many other brands. Just verify they are NOT SAE-SM rated and tagged oils.