The 3.0L Duramax LZ0 doesn’t get enough credit for how well-built it actually is. As a diesel mechanic, I’ve seen a lot of light-duty diesels over the years… and this engine is one of the few that genuinely impresses me. The internal design is stout — forged components, a strong bottom end, beefy rods, a well-supported crank, and a block design that’s built to handle real cylinder pressure. In this video, I break down the internal engineering of the LZ0 and why it’s a major step forward compared