Also, how does anyone explain the GM 3.8 going 200,000+ on 10w30. That engine is a TANK and it loves 10w30. I have seen 3.8 engines get abused day in and day out, and still keep on ticking. They now call for 5w30. My other half has an 05 impy. I run 10w30 in it and the cap clearly states 5w30.
When I worked in the lube center during my undergrad work, I saw countless cars, of all makes/models, running Pennzoil 10w30 with well over 100K on then and they kept coming back every 3K miles.