Winter/summer fuel never made much of a difference on my gas jobs... If anything, they did a little better.
Not a noticeable difference on the Duramax, either...
I get the same mileage on a tank, for my daily driving, summer, or winter... And winter idles a lot more, lol.
Not a noticeable difference on the Duramax, either...
I get the same mileage on a tank, for my daily driving, summer, or winter... And winter idles a lot more, lol.

