The Most Reliable Duramax Diesel Engine, Ranked

Choose the engine you think is the most reliable!

Author: Gregor Krambs
Updated on May 22, 2024 06:57
When shopping for a truck, selecting the right engine is crucial for ensuring longevity and performance, especially when it comes to diesel engines known for their durability and power. Duramax diesel engines have established a reputation in the automotive industry for being robust, but not all models perform the same under various conditions and over time. This site allows you to contribute to real-time rankings by voting for what you believe are the most reliable Duramax Diesel engines. By participating, you help create a valuable resource for others in making informed decisions. Each vote helps potential buyers identify which engines have stood the test of time, according to collective user experience and satisfaction.

What Is the Most Reliable Duramax Diesel Engine?

  1. 1

    LML (2011-2016)

    The LML introduced significant technological advancements, including the SCR system for reduced emissions. It's powerful and more fuel-efficient but has complex emissions systems.
    • Horsepower: 397 HP
    • Torque: 765 lb-ft
  2. 2

    LLY (2004.5-2005)

    The LLY is praised for its balance of performance and reliability. It introduced variable geometry turbocharging to the Duramax line.
    • Horsepower: 310 HP
    • Torque: 605 lb-ft
  3. 3

    LMM (2007.5-2010)

    The LMM was the first to include a diesel particulate filter (DPF) to reduce emissions. It's reliable but the DPF can be a maintenance issue.
    • Horsepower: 365 HP
    • Torque: 660 lb-ft
  4. 4

    LGH (2010-2017)

    Designed for commercial use, the LGH is a variant of the LML with some power restrictions for longevity in demanding applications.
    • Horsepower: 335 HP
    • Torque: 685 lb-ft
  5. 5

    LB7 (2001-2004)

    The original Duramax engine, the LB7 is known for its solid performance. However, it had issues with injector failures. Once fixed, it's very reliable.
    • Horsepower: 300 HP
    • Torque: 520 lb-ft
  6. 6

    LM2 (2019-Present)

    The newest in the lineup, the LM2 is a 3.0L inline-6 offering a different approach to the Duramax formula. It's known for its efficiency and smooth operation.
    • Horsepower: 277 HP
    • Torque: 460 lb-ft
  7. 7

    L5P (2017-Present)

    The L5P represents a significant improvement in power and torque, with a robust build to handle the increased output. However, it's still relatively new, so long-term reliability is being evaluated.
    • Horsepower: 445 HP
    • Torque: 910 lb-ft
  8. 8

    LLY/LBZ (2006)

    An overlap year where both LLY and LBZ engines were used. The early 2006 models had the LLY engine, and later models had the more powerful LBZ. This year is unique for offering both engines.
    • Horsepower: Varies
    • Torque: Varies
  9. 9

    LBZ (2006-2007)

    Known for its reliability and performance, the LBZ Duramax is often considered the best Duramax engine. It does not have the stringent emission controls of later models, which contributes to its longevity and power.
    • Horsepower: 360 HP
    • Torque: 650 lb-ft
  10. 10

    LMM (2007-2010)

    Similar to another entry but worth noting again for its introduction of emissions control technologies. The LMM balances performance and emissions compliance.
    • Horsepower: 365 HP
    • Torque: 660 lb-ft

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About this ranking

This is a community-based ranking of the most reliable Duramax Diesel engine. We do our best to provide fair voting, but it is not intended to be exhaustive. So if you notice something or engine is missing, feel free to help improve the ranking!


  • 1 votes
  • 10 ranked items

Voting Rules

A participant may cast an up or down vote for each engine once every 24 hours. The rank of each engine is then calculated from the weighted sum of all up and down votes.

Additional Information

More about the Most Reliable Duramax Diesel Engine

LML (2011-2016)
Rank #1 for the most reliable Duramax Diesel engine: LML (2011-2016) (Source)
Duramax Diesel engines have a strong reputation for reliability and performance. Many truck owners and enthusiasts trust these engines for their durability and power. These engines, produced by a joint venture between General Motors and Isuzu, have been in the market for years. They have proven themselves in various conditions and applications.

The history of Duramax Diesel engines dates back to the early 2000s. Over the years, they have undergone several changes and improvements. Each iteration has brought enhancements in power, efficiency, and reliability. These engines are known for their robust design and ability to handle heavy loads. They are often found in heavy-duty trucks and commercial vehicles.

One key feature of Duramax Diesel engines is their strong build quality. These engines are designed to withstand tough conditions. They have a cast-iron block and aluminum heads, which provide a good balance of strength and weight. The use of high-quality materials ensures that these engines last long and perform well.

Another important aspect is the advanced fuel injection system. This system helps in achieving better fuel efficiency and lower emissions. It also contributes to the smooth and quiet operation of the engine. The precise control of fuel delivery ensures optimal performance under various driving conditions.

Duramax Diesel engines also come with a turbocharger. This component plays a crucial role in enhancing the power output of the engine. The turbocharger compresses the air entering the engine, allowing more fuel to be burned. This results in increased power and torque, making these engines suitable for towing and heavy hauling.

Maintenance is another area where Duramax Diesel engines excel. These engines are designed to require minimal maintenance. Regular oil changes and timely servicing can keep them running smoothly for many years. The availability of parts and service centers also makes it easy for owners to maintain their engines.

Duramax Diesel engines are also known for their advanced cooling systems. These systems help in keeping the engine temperature under control, even under heavy load. This is crucial for the longevity and reliability of the engine. The cooling system includes a high-capacity radiator and efficient water pump, which work together to dissipate heat effectively.

The electronic control module (ECM) in Duramax Diesel engines plays a significant role in their performance. This module monitors various parameters and adjusts the engine operation accordingly. It ensures that the engine runs efficiently and responds well to different driving conditions. The ECM also helps in diagnosing issues and provides valuable data for troubleshooting.

In summary, Duramax Diesel engines are known for their reliability, durability, and performance. Their strong build quality, advanced fuel injection system, turbocharger, and efficient cooling system make them a preferred choice for many truck owners. Proper maintenance and timely servicing can ensure that these engines continue to perform well for years. The combination of these features makes Duramax Diesel engines a reliable option for those seeking a powerful and durable engine for their trucks.

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