I found this site about a week ago,and lurked for a couple days before signing in. This is a cool site! Now for my question. I have a 2001 2500HD with the 8.1 gas engine. I've had a bit of the cold start knock since new,nothing too bad,just annoying. I currently use M1 10-30 with Purolator filters. What do you suggest as far as an oil and filter combo to quiet it down a bit? Do synthetics do a better job of reducing the CSK noise or will a Dino be better? The M1 isn't making it any quieter. Thanks.