The engine is a 8 cylinder 6.2 liter. It starts out using 8 cylinders and progressively drops to 4 at highway speeds. The lifter failed, seized and gouged and ruined the block and camshaft. This preventable repair necessitated an entirely new engine. This happens to thousands of GM vehicles of a similar year, but GM only acknowledges years 2021-2024. They made a defective product, knew about it and refused to adress it