AM General Upgraded Humvee Engine Design

The manufacturer introduced a new 250-horsepower diesel engine to improve performance for light tactical vehicles.

Updated on Oct. 2, 2026 in Trucks

A close-up view of a high-performance diesel engine block on a metal workbench, highlighting technical industrial design. — AM General has introduced a 250-horsepower diesel engine for its Humvee line, designed to enhance acceleration and operational efficiency for light tactical vehicles. AI Illustration. Upload story photo >

Live Poll

Is upgrading existing military vehicle fleets a better long-term strategy than procuring new designs?

AM General has developed a new, more powerful diesel engine for its Humvee line, offering increased torque and improved fuel versatility. This engine is designed to enhance acceleration and top speeds compared to current models.

Why it matters

The upgraded powertrain aims to modernize the capabilities of light tactical vehicles, allowing them to perform better under demanding conditions. By increasing power and efficiency, AM General seeks to extend the operational relevance of its legacy platform.

The new engine delivers 250 horsepower and 745 Nm of torque, a significant increase from the 190 hp generated by the 6.5-liter turbocharged V8 in the current M1151 Humvee. The system supports multiple fuel types, including JP-8, F-24, and standard diesel.

The players

AM General

An Indiana-based manufacturer specializing in the production of light tactical vehicles and the iconic Humvee series.

U.S. Army

The primary branch of the United States Armed Forces responsible for land-based military operations and equipment procurement.

The details

The engine utilizes a modern common rail direct injection system coupled with electronic fuel controls to boost power and efficiency. This design allows for better fuel delivery and improved mechanical performance compared to previous iterations.

AM General built the first Humvee in 1983.
The Humvee NXT 360 was showcased by the company in 2021.
Russia launched a full-scale invasion of Ukraine in 2022.
The U.S. Army announced the cancellation of vehicle procurement in May 2025.
The new engine was presented at the AUSA symposium in March 2026.

Roadmap

This development follows the U.S. Army's May 2025 decision to halt excess ground vehicle procurement, highlighting a strategic shift toward upgrading existing fleets. By offering an advanced powertrain, AM General is positioning its legacy platform to remain competitive in an environment of reduced military spending.

While these military specifications primarily affect defense operations, the shift toward common rail diesel technology impacts maintenance expectations for specialized service shops handling fleet engines. Operators can expect more precise fuel delivery systems that differ from the mechanical setups of older Humvee variants.

The takeaway

The move to update the Humvee engine demonstrates how manufacturers adapt legacy systems to satisfy modern performance standards. Fleet managers should note that these high-torque upgrades require specific compatibility with electronic fuel systems.