Well Ace it's a pretty contentious issue at least with me since I've always viewed that using the best oil in all my vehicles is cheap insurance. I've spent the last 3 days, on and off, searching the net trying to get a handle on the oil being offered out there "today" primarily concerning the zinc (ZDDP) package. I'm probably more mixed up know than when I started. I've looked at Amsoil, Royal Purple, Castrol, Valvoline, Mobil 1, and Shell Rotella T. At present there is only 1 manufactorer that clearly states that their oil has 1200ppm (the minimum according to Hughes engine and others) and that's Valvoline VR1 at 1200-1300ppm. I should mention that I was unable to get a "clear" indication from my search on either Amsoil or Royal Purple, I guess it's top secret with these clowns. Shell Rotella T, the old standby at least in Canada, has dropped there contents down to 1100ppm and it will be lower next year.