has any one when from dino oil to full synthetic oil & had better m p g & what oil & how much better m p g did you get ? i have 2011 chevy 2500 Duramax pulling 35 ft 5th wheel..
In theory I like the idea of buying from a guy who uses synthetic and oil analysis because he's totally anal about maintenance.
But in the final outcome I'm that guy myself... so I buy new. Then I'm the one to break it in and maintain it to MY satisfaction. I'm not gonna tell you when I do the first oil changes. ;)