LN Engineering has a ton of good stuff, I think I posted that a long while ago when they actually had content (Zn/P) of many different brands of motor oils but I have not seen it on their site the last time I looked. I think they want you to send in your oil to have it analized now for a small fee. Might have just missed it. Great site. (I still like the Air cooled oil Motorcycle oil, but afraid to try it in something)
Also I agree with Mr. Mac, my cat cons will live a couple of years longer BFD, but when I have to rebuild my motor and all the waste that comes with that, I'll bet that it is a wash if not worse for the environment. When all said and done I think Cat cons are already highly controlled and recycled so seems like another dumb over the top 'green' thing, but don't know all the details besides longer life for the cats.
As it has been said may times "change it often" is the best thing I think. I just did a diesel oil change in my Excursion and got the last of the Rotella at the autoparts store that did not have the new formulation sticker, and even the diesel oils are getting the additive shaft too it seems. Same for Mobil 1 Delvac Diesel (or HD Turbo Consumer) stuff too. Wait until the big rig diesel truck guys find out they only get 300 k miles instead of 600 on a motor

(not sure what they really get)
Looks like when I purchse the next batch of racing oil I'll have to clearly state that the motor oil I'm purchasing will be for "Off Road Use Only" and I would never use it in an automobile that is used on public highways as that might be wrong.
I will say this that the Royal Purple has been OK in the Mustang until the pump shaft broke, and it ran about 20 seconds at almost full till until it siezed...
Sandy