The LLY came with a new variable-vane turbo ... Duramax engines. GM engineers also eliminated the DPF, combining it with the selective catalytic reduction (SCR) function into a single unit.

When the off-road focused Sierra AT4X debuted, it was equipped with just a single engine ... GMC's 3.0-liter Duramax was updated in 2023 with new steel pistons, a retuned turbo compressor, new ...