Does anyone know aproximately how much ZDDP is being used in M1 and Amsoil ASL/ATM? If you look at the VOA of 10w-30 ATM, it's only 900/800, which doesn't make sense. Then there are VOA's with Mobil having anywhere from over 1000ppm Zinc to as low as 900ppm. It seems there are huge descrpencies among UOA's and VOA's. It is my understanding that All Amsoil's oil use well over 1000ppm of both Zinc and P and Mobil being API, is ony using 750P and 900ppm of Zinc.