[QUOTE=370Z Purist;945116]ZDDP is a common additive to increase pressure resistance in oils. It has been tied to killing cats, although the kind of cat-killing this does is much worse on a car that consumes a lot of oil (namely rebuilt, low tolerance motors, not OEM equipment).
I agree with 370z purist ( not about the cats). I am not an auto mechanic but have worked on heavy AC centrifugal machines and screw machines. we perform 50 or more oil analisys every year on differant oils
and what seems common is that all oil have zink in differant amount depending on the brand. I looked up Mobile 1 oil on their web and their
MSDS sheet indicates that Mobile 1 also contains Zink, so is the mechanic saying that redline contains more zink and will damage converter faster then Mobile 1
