I'm currently running Amsoil series 2000 0w-30 oil in my car. One thing i noticed with my engine is that with Mobil1 5w-30 and the Amsoil, the engine seems to run alittle more noisy during start up. You hear more ticking and mechanical noises especially during cold morning starts. Once it warms up the noise is gone. I noticed with thicker weight oils, the engine seems to be more quiet. Whats a general good weight to run in the winter/summer for bmw's I6 ? I'm want only the best stuff for my engine especially with the supercharger. I might try Redline or the Amsoil new european formula 5w-40. Any experts in here?