2024 6.6 Duramax Fuel Mileage. However, the average fuel mileage for. The truck's l5p duramax diesel engine received a substantial bump in power and torque thanks to a stout list of upgrades, including a new turbocharger, improved piston design, enhancements to.

A camper is in my future plans. Looking at a new 2024 at4 and just curious if the 10 speed transmission helps with mpg.