HaulinBut

Yeah, Yeah, I know.......this topic has been beat to death.....so don't read it.
For those who can't resist, you might just want to glance over the comprehensive report done by this firm. LNEngineering.com/oil.
It is 17 pages of knowlege they are willing to share, and in my opinion holds some worthwhile reading.
It got my interest because I build air-cooled race engines for a living and after a couple thousand engines, I just lost my first-ever cam on the dyno. The article centers on the substantial reduction of Phosphorus and Zinc (apparantly to do with cat. converters). Sure nuff, the stuff I was running was a brand that had reduced both elements drastically. I went around to 7 different retail stores over the weekend, trying to find some P/S Oil Extender to no avail.....all gone.
There are also some good and surprising statements in there, such as one stating that oil has a "sweet spot" and that you can actually increase wear by changing your oil too often! That one surprised me.

BigBlue

Doesn't surprise me. The oil needs to be left in there as long as the additives are still good to help clean stuff and lubricate and get rid of all the acids and harmful stuff in the motor. If it's pulled out before it's done it's job then those particles will still be stuck in the motor.