Quote:

Would using 15w40 Chevron Delo with STP additive contain enough zinc to safely operate with a flat tappet Comp cam? I am currently running Valvoline VR1 20w50, which has lots of zinc, but want to run a thinner oil to pick up some power and fuel mileage.



Justin,

Brad Penn 30w may work for you. I use it with a very aggressive FT cam. IIRC, Isky sells ZDDP as an additive if you want to go that route.