I've been using AMSOIL SAE 5W30 for a while. I'm trying to understand the difference between the 0W30 AMSOIL Series 2000 AMSOIL SAE 5W30 Synth, as a newbie. I frequently Auto-X & occasionaly go to a drag track & was wondering what you recommend. I have the GM 2200 engine that recommends a 5W30.