The Evolution of the DURAMAX Diesel Engine

The evolution of the DURAMAX diesel engine

The evolution of the DURAMAX diesel engine has been a wild ride indeed. More than 2 million DURAMAX engines have been built since its inception over 20 years ago. They’re in Chevrolets and GMCs. They’ve been in trucks, pickups, vans, and medium duty trucks as well. The engine always packs a punch and delivers power.

So, here’s an abridged version of the story of the DURAMAX Diesel Engine.

What is the DURAMAX Diesel Engine?

The DURAMAX is a 6.6-liter diesel V8 engine produced by DMAX. That’s the joint venture between General Motors and Isuzu. Starting in 1998, the venture produced the first high pressure, common rail direction injection power plant in the US. That means the engine packs a punch.

The first engine was installed in 2001 in Chevrolet and GMC trucks. 23 years after the project was first conceived millions of vehicles now have the engine installed.

A Brief History of the DURAMAX Diesel Engine

2001-2003 LB7

The first DURAMAX diesel engine debuted in 2000. It was the LB7 with 300 hp and 520 lb-ft of torque. With ¾ and 1-ton trucks. The 6.6-liter V8 turbodiesel engine featured several aluminum heads with 32 valves on a cast iron block. It had high pressure, a common rail, and a direct fuel injection.

There was also a fixed-geometry turbo and several injectors mounted under the valve covers. There was also a catalytic converter installed. This was the engine installed for the 2001 Chevrolet and GMC trucks. For the 2003 versions of the Chevrolet Kodiak and GMC Topkick, they came fitted with the LB7 as well.

2004-2005 LLY

The 2nd generation of the Duramax was introduced for the 2004.5 model year. Changes included a new variable geometry turbo setup which was responsible for a 10 hp climb in power for a total of 310.  Torque remained the same at 520 ft lbs, but came on 200 RPMs sooner (1600 rpm vs. 1800 rpm.) Although the LLY is desirable because it is void of most emission controls, but it was also plagued by overheating issues due to undersized cooling components.

2006-2007 LBZ DURAMAX Diesel Engine

In 2006, the LBZ DURAMAX was introduced for the ’06 model year. It had a lot of improvements which made the engine produce over 360 hp and 650 lb-ft of torque. These were huge improvements over the preceding designs.

The LBZ soon became a favorite of tuners thanks to the stronger block design and the larger connecting rods. There was also a new piston design and new heads which could handle greater pressure. With greater fuel pressure levels and larger fuel rails, came greater performance. A large EGR cooler setup was also added.

This combined with the addition of a new 32-bit engine computer improved power efficiency and cut down on emissions.

2007.5-2010 LMM

The LMM was introduced for the 2007.5 model year as a response to the ever-increasing emissions demands be placed on manufacturers. Continuing to build off the same bore and stroke of the previous generations, the newest Duramax engine also introduced the first DPF system (diesel particulate filter) on a GM truck. Power for the LMM Duramax came in at a respectable 365hp and 660lb-ft of torque.

2011-2015 LML

The LML Duramax, introduced for the 2011 model year was a powerhouse. Coming out of the gate with 397hp and 765 lb/ft of torque, this Duramax diesel featured an advanced fuel injector design and increased line pressure to 30,000 psi compared to 26,000 on the LMM. To support the increased fuel pressure the LML was fitted with a Bosch CP4.2 lift pump compared to the CP3 on previous years. The cp4.2 is less desirable for tuners due to a 20% downgrade in flow than the cp3. The LML also had two major emissions upgrades including the addition of selective catalytic reduction (SCR) and a diesel exhaust fluid (DEF) system.


This is a redesign of the original DURAMAX diesel engine. Only the stroke and bore dimensions are similar to the past engines. The latest generation is quitter and smoother. The changes to the engine have improved fuel economy and durability and cut down on emissions. Power has also increased to a whopping 445 hp and torque to a monster 910 lb-ft.  This power upgrade is thanks to an upgraded camshaft profile, a new electronically controlled, variable vane turbo and a new air intake system with patent-pending functional hood scoop.

Pair the DURAMAX Diesel Engine With the Best Apparel from Aggressive Thread

Duramax spells power and reliability. You should get apparel to match that power. With Aggressive Thread you can choose the best Hats, T-shirts, and Hoodies to go along with all that power. So, head over to OUR Duramax Collection and complete your look for power and style.

Disclaimer: Aggressive Thread is an Amazon Affiliate member. Clicking on any links in this post may earn us a small commission. 

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