http://www6.autonet.ca/Maintenance/Fluids/story.cfm?story=/Maintenance/Fluids/2007/03/30/3880169-ap.html

probably being overly cautious. does it hurt to change at 3,000 miles, no. But 5,000 isn't likely a problem for most either. The other half of the life rating is time. I'm curious to know if the "or every 3 months" rule is valid. I would think it is a fabrication by those with a vested interest in having us all change or oil at least 4 times a year.