Been doing some reach on the 5w50 the new track pack gt comes with from the factory. I have read a lot of the gt500 guys are running different grades with good success. I plan on driving this car year round and that includes Michigan winters. A 50 grade oil seems like it would be way ton heavy in the winter. Doesn't sound like there is any changes ton the motor just the oil cooler. I am thinking the regular 5w20 or even a 5w30 would be a better fit for me. Dont plan on tracking car much I was really after the torsion diff. What are peoples thoughts?