Sorry folks, I'm just full of dumb questions this month. '06 Toyota owner's manual simply advises to use an "ILSAC multigrade oil" in the 5W-30 grade. There's no reference to API SM, or the like. I'm assuming Toyota means a GF-4 5W-30? Here's my second dumb question. The local Auto Zone has in stock a couple cases of GC but it must be a little old since it's all SL oil. Do you folks think this GC would be okay in the '06 Toyota? Thanks.