Exactly. It is harmful to converters and he warns about that. He also discusses use of Zinc and all the myths and hype it brings. He tested a lot of oils adding zinc and it made the oil a lot less effective. He will recommend you use for example--the Valvoline Hi Mileage full synthetic 5w-30 over their Valvoline racing oil with more zinc, etc...I have asked him things on his blog and will get back to you within hours typically Just be nice when asking the question Ask him if he has the specs..... A lot of people have gone there to fight with him and he talks about that in his dissertation. 5 quarts of Amsoil Signature series 5w-30 is think is 44.00 at my local auto parts store. He says if you use oils on his top 10 list you won't take out a cam.
I am done...Oil discussion can be tough crowd to work with! .I only mentioned this originally for guys interested in oil like I am.
Not sure if this is directed at me or not...either way, I'm not trying to be difficult (and I'm genuinely sorry if I came across that way). Like I said - the guy has some good information on his site, and it is definitely worth a look. Even still, some of his advice should be taken with a grain of salt. ZDDP is a proven, effective anti-wear agent. It is beneficial up until around 1800 - 2000 ppm, at which point it can start to cause corrosion inhibitors to become less efficient.
If you're interested in oil, you should check out some (peer-reviewed) tribology articles on the subject, some of which are open-access and can be found via Google Scholar searches.
