My wifes car has been on a steady diet of M1 5W-30. Would there be any adverse effects to switching her car to GC 0-30 I scored 5qts of GC green at Auto Zone today.
As a fellow Ion owner, I would suggest you are wasting your money. My guess is some TropArtic blend would get you to the finish line quite nicely. Save that good stuff for the Porsche...