hard to find Castrol European Formula 0W30 here in Toronto. I did try with no luck. I plan to run Castrol Edge 5w-20 in the winter here and swap them out come the summer. Any one knows any reasons I shouldn't do that?
http://www.focfl.com/tech/articles/oil.html
Here's an article from a very knowledgeable Oil expert, "Dr. Haas is a physician and surgeon. He graduated from the University of Florida with a degree in biochemistry with honors. He studied motor oils since high school where he did independent studies on this topic. He studied the properties of viscosity. "
After taking 2 days to digest the article, I chose to adjust my beliefs to his data, and go with a thinner oil rather than thicker. My winter drives rarely gets up to operating temperature and thinner oils seems to suit my immediate needs better.