2025 Yukon At4 Ultimate Release Date. The lz0 diesel engine is also notable for its availability with the 2025 gmc yukon at4 and at4 ultimate trim levels. Elevation, at4, at4 ultimate (new for 2025), denali, and denali ultimate.

Production of the 2025 yukon was originally slated to begin on monday, october 7 th, but was delayed as the result of a temporary plant shutdown stemming from a parts shortage. Yukon’s premium capability is about to level up with new enhancements for 2025.