2025 Gmc Sierra 2025 Denali Ultimate Specs. The gmc sierra 1500 denali ultimate’s engine options are limited to the 3.0l i6 lz0 turbodiesel duramax engine or the naturally aspirated 6.2l v8 l87 gasoline engine. Find specs and features for the 2025 gmc sierra 1500 including dimensions, horsepower, engine, capacity, fuel economy, transmission, safety rating, drivetrain and more.

Complete specs for 2025 gmc sierra 1500. The gmc sierra 1500 denali ultimate’s engine options are limited to the 3.0l i6 lz0 turbodiesel duramax engine or the naturally aspirated 6.2l v8 l87 gasoline engine.