How much horsepower does a 3500 HD Duramax have?

The current 3500HD Duramax delivers 470 horsepower, with about 975 lb-ft of torque. Earlier versions were rated at 445 horsepower and 910 lb-ft of torque.

Understanding the 3500HD Duramax horsepower

The 3500HD uses a 6.6-liter V8 turbo-diesel Duramax engine paired with an automatic transmission to provide strong pulling power for heavy-duty workloads. Horsepower figures for this engine have evolved over its lifecycle, with updated generations bringing higher output while maintaining the same core design and torque delivery that buyers rely on for towing and payload.

Model-year horsepower figures

The following figures summarize the official factory ratings by generation to help compare model years:

• 2017–2023: Duramax 6.6L Turbo Diesel (L5P) — 445 horsepower, 910 lb-ft of torque.


• 2024–present: Updated Duramax — 470 horsepower, 975 lb-ft of torque.

These numbers reflect standard configurations and are intended for comparison across model years. Exact output can vary by trim, emission certification region, and any factory-supported towing or performance packages. Always check the window sticker or GM’s official spec sheet for your specific build.

What this means for performance

Horsepower, combined with torque, governs acceleration and overall pulling capability. The Duramax in the 3500HD is designed to deliver robust low-end torque for heavy trailers and steep grades, while the higher horsepower figure in newer models helps with quicker highway acceleration when unladen. For buyers evaluating a 3500HD, the latest 470 hp/975 lb-ft configuration represents the peak output GM currently markets for this platform, with older builds offering strong but slightly lower numbers.

Notes for prospective buyers

When shopping, verify the exact horsepower rating on the vehicle’s window sticker or build sheet, since trims, markets, and optional packages can influence the official numbers. If you’re comparing to previous generations or different Duramax variants, keep in mind that torque tends to be the more critical metric for towing capacity and hill-climbing performance.

Summary

In its current form, the 3500HD Duramax makes 470 horsepower and roughly 975 lb-ft of torque. Earlier generations topped out at 445 hp and 910 lb-ft. For anyone considering a heavy-haul pickup, the newer rating offers a noticeable boost in acceleration and towing responsiveness, though the most important factor remains the engine’s torque delivery and the vehicle’s chassis and drivetrain setup. Always confirm the exact specs for the specific truck you’re considering.

Is a 6.7 Cummins better than a 6.6 Duramax?

The Cummins 6.7L is generally favored for higher torque and towing capacity, while the Duramax 6.6L often has a slight edge in horsepower and a reputation for a smoother, quieter ride. The Cummins is an inline-6 engine, and the Duramax is a V8. Performance can vary by specific model year, with the latest iterations of each engine being very competitive.
 
This video compares the power, torque, and other specifications of Cummins, Duramax, and Power Stroke engines: 1mTruck MasterYouTube · Dec 2, 2020
Cummins 6.7L 

• Configuration: Inline-6 
• Torque: Higher torque, with the High Output version reaching up to 1,075 lb-ft, making it ideal for heavy towing. 
• Horsepower: Generally lower horsepower than the Duramax, but still powerful. 
• Driving feel: Often described as having a strong, low-end pull, feeling less phased by heavy loads at lower RPMs. 
• Engine history: A long-established brand with over 100 years of history, used in Ram trucks since 1989. 

This video provides an overview of the performance of the 2024 Silverado Duramax and 2023 High Output Cummins: 58sBen HardyYouTube · Apr 8, 2023
Duramax 6.6L

• Configuration: V8 
• Horsepower: Generally higher horsepower, with some models reaching up to 470 horsepower. 
• Torque: Lower torque than the Cummins, but still very capable. 
• Driving feel: Often praised for a smoother, quieter ride, with a driving feel that can feel quicker at wide-open throttle. 
• Engine history: Has been used in GM vehicles since 2001. 

Which one to choose?

• Choose the Cummins 6.7L if: Your priority is the highest possible towing and hauling capability, and you value the strong, low-end torque for heavy loads. 
• Choose the Duramax 6.6L if: You want more horsepower for quicker acceleration and prefer a smoother, quieter, and more refined driving experience. 

What is the difference between 2500HD and 3500HD Duramax?

The main differences between a 2500 and a 3500 Duramax are their towing and payload capacities, which are enabled by a more robust rear suspension and the option for dual rear wheels on the 3500 model. While both trucks often share the same Duramax 6.6L engine and Allison transmission, the 3500 is designed to carry and pull significantly more weight.
 
Towing and payload capacity

• The 3500 has a significantly higher towing and payload capacity, especially when equipped with dual rear wheels (DRW). 
• The 2500 is capable of heavy-duty tasks, but the 3500 is built for the most demanding hauling and towing situations, with a maximum tow rating potentially reaching up to 36,000 pounds. 

Suspension

• The 3500 features a beefier suspension to handle its higher capacity, often including extra "helper" leaf springs that are not on the 2500. 
• A 2500 model with the max tow package can have the same suspension components as a 3500, but it will still have a lower overall capacity due to other differences. 

Rear wheels

• The 2500 is only available with single rear wheels (SRW).
• The 3500 offers both SRW and the option of a dual rear wheel (DRW) configuration, which provides greater stability and weight-carrying ability. 

Body, chassis, and interior

• The body, chassis (with the exception of the DRW option), and interior are largely the same between the two models. 
• The only significant physical difference is often a slight increase in height for the 3500, which is necessary to accommodate the larger suspension and wheels. 

How much horsepower does a 2025 6.6 Duramax have?

The 2025 6.6L Duramax turbo-diesel has 470 horsepower and 975 lb-ft of torque. This engine is available in heavy-duty trucks like the 2025 Chevrolet Silverado HD and is paired with a 10-speed Allison automatic transmission. 
You can watch this video to learn more about the 2025 Duramax Silverado's performance: 1mThe Fast Lane TruckYouTube · Jan 30, 2025

• Horsepower: 470470470 hp
• Torque: 975975975 lb-ft
• Transmission: 10-speed Allison automatic
• Peak Torque: 90%90 %90% of peak torque is produced from 1,5501 comma 5501,550 to 2,8502 comma 8502,850 rpm for strong performance when towing.
• Towing Capacity: The diesel engine provides a max available trailering weight of up to 36,00036 comma 00036,000 lbs. 

How much horsepower does a 3500 Duramax diesel have?

6.6L Duramax Turbo-Diesel Engine
Drivers looking for extreme performance often upgrade to the Silverado 3500's available 6.6L Duramax turbo-diesel engine. The turbo-diesel engine provides a maximum towing capacity of 36,000 pounds, along with 470 horsepower at 2800 rpm and 975 lb. -ft.