DMAX Limited was formed in 1998 when General Motors (GM) and Isuzu joined forces to create a diesel engine. Their plant was to be the first high-pressure common-rail direct-injection plant for diesel engines in the United States. The Moraine, OH based plant has built approximately 1.5 million engines to date.
The first engine was produced in 2000 with the introduction of the 6.6-liter V-8, LB7 Duramax. The LB7 boasted 300 horsepower, 520 foot-pounds of torque, and was a significant improvement over GM’s previous indirect-injection diesel engine. Not only was it a significant improvement over their previous engine, it was also significantly more advanced than the engines that Ford and Dodge used in their trucks. As a matter of fact, it wasn’t until 2008 that Ford introduced a high-pressure common-rail diesel engine.
In 2004 the LLY Duramax was introduced. This model featured an improved valve design (for easier repair) and a more powerful 310 horsepower engine with 605 foot-pounds of torque. The emissions system was also improved upon by adding an exhaust gas recirculation system, which routed some of the exhaust through a cooler before sending it through the engine for a second burn. A variation of this engine was used in Hummer’s H1A.
In 2006 Duramax released their vastly improved LBZ model, which quickly became a favorite. With 360 horsepower and a whopping 660 foot-pounds of torque, it was their most powerful engine thus far in their venture. Improvements included a 32-bit engine computer, stronger block design, new piston design, higher fuel pressure levels, and larger fuel rails. The LBZ proved to be the most popular turbo diesel engine that Duramax had built thus far in their existence.
The LML is the current Duramax engine. It was introduced to the market in 2010, and has been called “The Clean Machine” by some due to its meeting of very stringent emissions laws. This newest engine features an incredible 397 horsepower and produces 765 foot-pounds of torque. One of the key features of this engine is that it will run on fuel blends of up to 20% biodiesel without having any negative effect on the engine or voiding the warranty.
Duramax diesel engines have always been and continue to be a game changer when it comes to the manufacture of diesel engines. All others in the industry emulate the constant technological improvements they implement into their engines. It should be interesting to see the next engine they introduce.