see my sig

 

Randy, why 10/40? I plan to make the switch to synthetic oil using Mobil 1 w/ Mobil 1 filter, is 5w30 a good grade? I know with the reg oil my dealer uses in my car is 5w30. Should I keep using that grade or change to something different?

 

I am planning on switching to synthetic at my 7500 service and my dealer uses Mobil 1

 

it's supercharged and not a bad idea.

 

Amsoil and nothing else.