2024 6.6 Duramax Specs. The increased power has increased. 2 of mine run delo 5w40 year round and the newest one i'm trying the ultra low ash delo 600 adf 15w40.

2 of mine run delo 5w40 year round and the newest one i’m trying the ultra low ash delo 600 adf 15w40. 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.