I would imagine most 5w30s are actually 10w20s by the end of a 3000 mile interval. If you get the viscosity at 40c on your UOAs, that would give you a better idea of how the low end viscosity is holding up, and I'd be willing to bet most 5w30s end up with their viscosity at 40c being quite a bit different than the starting point. Wearcheck Canada and Wearcheck USA will give you viscosity at 40c if you ask for it (for no charge) so if anyone is running 5w30 dino and getting their UOA from them, be sure to ask for the 40c viscosity test.
[ January 12, 2004, 09:04 PM: Message edited by: Patman ]