History of the Duramax

History of the Duramax



The Duramax has become a popular name among diesel enthusiasts. It put General Motors at the top of the pack for diesel trucks. When we refer to GM (General Motors) we are referring to the Chevrolet and GMC brands.

GM has had diesels in their truck line up for years, but did not have good success early on in that
department. Their previous engines were a V-8 style engine that struggled in the diesel truck market and consumers began looking at other manufacturers for a better option. Isuzu Motors had been building diesel engines for years and was one of GM’s partners. So began the alliance with GM and Isuzu. This new partnership resulted in a fast-track to provide the GM trucks with a new power plant that was released in the 2001 model Chevrolet and GMC HD Diesel trucks. This new business venture between GM and Isuzu created a new company called DMAX Ltd and was owned 60% by GM and 40% by Isuzu.

They built a 650,000 square foot engine manufacturing and assembly plant in Moraine, Ohio. The name
Duramax was chosen to signify durability and maximum power, along with cleanliness and fuel

The Duramax engine displaces 6,599 cubic centimeters or 6.6 liters as it is known by. It uses a direct
injected fuel system which was the first of its kind in a pickup truck. It was turbo-charged with a 90-
degree V-8. It had aluminum cylinder heads with 4 valves per cylinder. The Duramax Diesel was an
immediate success as it achieved the best in class honors for both operating quietness and smoothness.

GM’s previous diesels only had about 3% of the diesel truck market. The new Duramax engine rocketed
GM to 30% market shares and has continued to be successful.

The first Duramax rolled off the assembly line in July 17, 2000. There has been a number of
improvements to the Duramax over the years. In 2001, the Duramax was introduced as the LB7 with
235hp and 500lb-ft of torque. This engine lasted into 2004 when it was rated at 300hp and 520lb-ft of
torque. Mid-year in 2004, they introduced the LLY version of the Duramax which was rated at 310hp
and 520lb-ft of torque. In 2006, GM introduced the LBZ version which had 360hp and 650lb-ft of torque.
Again mid-year in 2007, the LMM was introduced which had 365hp and 660lb-ft of torque. The LMM
lasted until 2011 when it was replaced with the LML which was rated at 397hp and 765lb-ft of torque.
In 2017, the L5P was introduced with 445hp and 910lb-ft of torque and is the engine you would get in
any new GM diesel truck you purchase today. In March of 2017, the 2 millionth Duramax rolled off the
assembly line. This new Duramax is advertised with the highest horsepower of all the diesel pickup
truck engines on the market today.