Heres a question for you Amsoil guys. I have been running Amsoils 15W-40 synthetic diesel/marine oil in my gas road vehicles, and in my F-350 powerstroke diesel. But since I traded the diesel for a gas, could I continue to use this 15W-40 in all my gas vehicles? Or should I switch to Amsoil 10W-30 synthetic? Thanks in advance.