Has anyone have any thoughts about using STP Oil Treatment as a supplement for ZDDP in their oil ? The bottle says it has ZDDP in it but I don't know how much.

Last edited by Peggy M; 07/10/2024 4:33 PM. Reason: added more info to the title

"One thing about trains, it doesn't matter where the're going, what matters is, deciding to get on." - Polar Express