Read #1 above. Shelf oils are high detergent, adding you zinc makes you feel good, but the detergents are fighting your additive, not the way to go. Buy the right oil from the start.
Specialty oils like Brad Penn and Joe Gibbs are typically lower in detergents than the run-of-the-mill stuff that you can pick up at AutoZone. While Rotella's deisel oil has high ZDDP content, it also has higher detergent concentrations than run-of-the-mill oils intended for use in gasoline engines.
"When I'm in a slump, I comfort myself by saying if I believe in dinosaurs, then somewhere, they must be believing in me. And if they believe in me, then I can believe in me." - Mookie Wilson
