Originally Posted by syclone
.. lighter weight is better for colder weather. the thinner oil allows for easier startup and better protection during the first stages of startup..
Yes, hence the lighter viscosity in winter...it's 0
W-30. Personally, I don't take many short trips, so I prefer heavier oil. I want optimal engine protection when my engine is warm. But like Chad said, I doubt 0 weight would really make much of a difference. It's all theoretical anyway.