09/28/2026
GM’s new V8s are making more power, but the bigger story might be what they’re doing behind the scenes to make sure they actually hold up.
The new 5.7L V8 makes 402 hp and 428 lb-ft, while the 6.6L makes 481 hp and 501 lb-ft. But with the outgoing 6.2L making headlines over crankshaft and connecting-rod manufacturing issues, GM knows people are going to be watching reliability just as closely as horsepower.
GM says the new engines are a clean-sheet architecture, and by the time the 2027 Silverado and Sierra reach dealerships, development teams are expected to have logged more than 2.4 million km, or roughly 1.5 million miles, of road testing. On top of that, more than 200 engines at different stages of production are being put through dyno, durability, NVH and other laboratory testing. GM is also using advanced analytics and a new AI-supported database to help catch potential problems during development.
The engines themselves have been heavily reworked too: higher compression, larger throttle bodies, new intake manifolds, a combination of direct and port fuel injection, and a completely new lubrication system. GM says several components were redesigned specifically for greater robustness.
So yeah, 481 hp from a naturally aspirated truck V8 is impressive, but to me the real question is going to be durability.
Did GM do enough testing to win people back after the 6.2L issues, or are you waiting a few years before trusting these new V8s?
