2024 Gmc Denali 2024 Duramax

2024 Gmc Denali 2024 Duramax. Looking at a new 2024 at4 and just curious if the 10 speed transmission helps with mpg. I ordered a 2024 gmc sierra 3500 denali ultimate in redwood metalic single wheel and purchased it on 1 june 2023.

I ordered a 2024 denali and now i’m worried. Truck ran fine no issues, but around 600 miles i.