If you got you oil changed at the dealership, you may want to confirm that you received the right grade of oil. Quite a few dealerships still use 5W-30 in their bulk tanks because it is cheaper instead of 5W-20 or 0W-20.

The Toyota Technical Service Bulleten (TSB) and the Owner's Manual both state that 5W-20 is OK. But, for better fuel economy & better cold starting performance use 0W-20.

More recently, Toyota announced 0W-20 across the board:

In the July 1, 2008 Edition of Flashpoint, ILMA has announced that Toyota has officially decided to switch the recommendation on engine oil for certain vehicles from SAE 5W20 and SAE 5W30 to SAE 0W20.

ILMA reports that these changes will affect all Toyota brands, including Toyota, Scion and Lexus. The change will also appear in owner's manuals.

No further information is offered on timing or specific vehicles.

Please read more about this announcement here:
http://newsmanager.commpartners.com/...8-07-01/1.html

Here is a link to download the TSB:
http://www.chrysanindustries.com/pdf..._tsb071002.pdf

Hopefuly, As more owners specifically request the 0W-20, the dealerships will be motivated to carry the 0W-20 in bulk so that the "BULK OIL" = 0W-20.