Hi guys, Ive done a search and havent quite found what Im looking for. So Im asking for opinions, fact or just plain help.
I have an 04 GTO, LS1 with 11,500 miles on it. I used M1 5-30 per GM to about 9500 miles, then switched to M1 0w-40. Its been in for 2000 miles or so and the motor is a bit...