General Motors has enjoyed many collaborations, but for diesel heads, the most iconic and industry-shaping was with Isuzu. At the turn of the new millennium, the two companies partnered together to release the legendary 6.6-liter V8 engine that pioneered the Duramax brand. Ever since, the name Duramax has been almost synonymous with Isuzu engineering. This history-shifting collaboration has, over the years, left many diesel enthusiasts assuming that every one of these engines slapped under the hood
of the Chevrolet or GMC still runs hot with Isuzu DNA.
However, the truth is, not all Duramax engine generations come from the same family tree. A perfect example is the 3-liter Duramax. It's a turbocharged in-line six diesel engine that featured in many of GM's lines up, both for Chevy and GMC SUVs and trucks. It came in the Silverado, Sierra, and even the Tahoe. The 3-liter Duramax featured a cast aluminum block and head, high-pressure common-rail fuel injection, Variable Geometry turbocharger, and was paired to a 10-speed automatic transmission.
The result was 277 horsepower and 460 lb-ft of torque (305 hp and 495 lb-ft of torque on newer models). The 3-liter Duramax is often, innocently, mistaken for an Isuzu engine -- it's not. If anything, it is purely the product of General Motors' engineering developed in Michigan. This might be a little confusing if you are just getting to know Duramax engines, and to get a clearer picture, we need to look back into the history of the GM-Isuzu collaboration.
Read more: The Most Reliable Duramax Diesel Engines (And Which To Avoid) According To Owners
GMC-Isuzu Partnership And 3.0-Liter Duramax Origin
The 3-liter Duramax comes from a long line of engines with a collaboration that began in the late 1990s by General Motors and Isuzu called the Dmax Limited, in Moraine, Ohio. The lovechild of this historic union was the Duramax engine, and first inline was the 6.6-liter Duramax V8 popularly known by diesel heads as the LB7. This engine, co-developed by Isuzu (with GM input, of course), was built in the United States and slapped onto the 2001 Chevrolet Silverado and GMC Sierra HD trucks.
Over time, General Motors took over DMAX Ltd. Still, Isuzu engineering remained on the 6.6-liter platform through its generations on the LB7, LLY, LBZ, LLM, LML, and L5P. Therefore, when you see the Duramax brand from the older, heavy-duty models, it's directly related to the GM-Isuzu partnership. However, the 3.0L Duramax (RPO LM2 and the LZ0) is not a product of the General Motors-Isuzu collaboration. Here's the truth. While Isuzu still has a knack for developing good diesel engines, Duramax today is a GM-owned trademark used as a brand umbrella for all its diesel engines (including those not connected to Isuzu).
The 3.0L inline-six turbo-diesel was built in-house in Flint, Michigan (meeting U.S emissions), and introduced for the 2020 Silverado 1500 and GMC Sierra 1500 as a light-duty option. It features modern architecture that's not related to the pioneering 6.6L V8. It was paired to the GM-developed 10-speed Hydra-Matic 10L80 automatic transmission, and featured an aluminum block, forged steel crankshaft, and a belt-driven oil pump.
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Read the original article on SlashGear.
