My choices for oil are Mobile 1 ESP 5w30, Mobile 1 ESP formula 5w30 ( for a little while), Mobile 1 ESP 0w40, and Valvoline MST 0w40. I am thinking about using the Valvoline in the summer and the Mobile 1 5w30 in the winter. I do not know a lot about oil, so I was hoping some of the experts...