How much horsepower does a 2011 6.6 Duramax have?
The 2011 GM heavy‑duty 6.6-liter Duramax diesel produces 397 horsepower, with peak torque around 765 lb-ft. This rating applies to the LML variant used in Chevrolet Silverado 2500HD and GMC Sierra 2500HD/3500HD models.
What the numbers mean for the 2011 Duramax
In 2011, GM's Duramax lineup adopted the LML designation, featuring a high‑pressure common‑rail fuel system and emissions controls that included a diesel particulate filter. The official peak power is 397 hp at about 3,000 rpm, with peak torque of 765 lb-ft available across a broad RPM range to support heavy towing and hauling.
Key specifications
Here are the official peak specifications commonly cited for the 2011 Duramax LML in GM heavy‑duty pickups.
- Engine: 6.6-liter V8 Duramax (LML)
- Horsepower: 397 hp at 3,000 rpm
- Torque: 765 lb-ft (1,037 Nm) around 1,600–2,800 rpm
- Fuel system: High‑pressure common‑rail diesel
Note: Real-world output can vary slightly by vehicle, market, and testing protocol, but 397 hp and 765 lb-ft are the commonly cited figures for the 2011 model year.
Context and evolution
Prior generations of the Duramax 6.6L included the LBZ engine (2006–2007) with about 360–365 hp and 660 lb-ft of torque. The LML era introduced stricter emissions controls and improved power delivery, culminating in the 397 hp/765 lb-ft rating that defined the 2011–2016 trucks. This shift helped GM maintain competitive performance in the heavy‑duty segment while meeting newer clean‑diesel standards.
Summary
For the 2011 Duramax 6.6L, the standout figure is 397 horsepower, complemented by 765 lb-ft of torque. The LML engine married stronger output with advanced emissions technology, delivering robust towing and hauling capability for GM’s heavy‑duty trucks.
