When it comes to outstanding fuel efficiency that doesn't compromise on capability, the new Duramax® 3.0L Turbo-Diesel I-6 engine for the 2020 GMC Sierra 1500 is a seriously smart powertrain.

This latest engine builds off a deep understanding of the diesel powertrain space, earning the legendary Duramax badge by the high level of attention paid to maximizing its durability and efficiency that other diesel engines in the GMC family are known for.

Offering up to an EPA estimated 30 MPG highway, the Duramax 3.0L Turbo-Diesel not only gives you the most efficient Sierra 1500 ever, but is an ideal powertrain for off-road adventurers with a powerful 460 lb-ft of torque and best-in-class 277 diesel horsepower.†

It also marks the first-ever inline-six turbo-diesel for GMC's full-size light-duty truck, an engine design that helps enable a smoother driving experience, and will be available fall of 2019 on the Sierra SLE, Elevation, SLT, AT4 and Denali models.
It has been paired with a 10-speed automatic transmission, so this engine is not only powerful and efficient, but responsive and smooth while at work or play.


Diesel engines are often recognized for their capability and grit to tow, as well as their driving range and fuel economy.

And the Duramax 3.0L Turbo-Diesel is no different. With up to 30 MPG highway, this powertrain offers you the most efficient Sierra 1500 ever. That's because it was engineered to include multiple advanced combustion technologies to bring about high levels of efficiency, helping you spend less time and money at filling stations and more time getting to where you want to go.



The efficiency of this engine even extends to its block, which was made from a lightweight cast aluminum alloy. Capable of withstanding the high combustion pressures of a diesel engine, it resulted in a 25 percent savings in mass over a comparable cast iron engine block.

It has a high 15.0:1 compression ratio, so situations where the engine is really working will still provide the best possible fuel economy for those high-demand conditions. And for times when you're at a standstill ─ such as a traffic light or stop-and-go traffic ─ the Duramax 3.0L Turbo-Diesel has start/stop technology (with disable switch), which will turn the engine off for a short period of time.

The Duramax 3.0L Turbo-Diesel also uses Active Thermal Management to target specific areas of the powertrain system for heating and cooling. This not only seamlessly helps the engine warm up quickly but maintain an ideal temperature for performance and minimize fuel consumption. Ceramic glow plugs are used as well, so cold starts are quicker and warm-up times in colder weather are fast enough for the engine block heater to go unneeded until temperatures drop to -22 degrees F.

To achieve its class-leading 277 diesel horsepower with minimal impact on fuel economy, the Duramax 3.0L Turbo-Diesel has a variable geometry turbocharger to maximize the amount of available boost across the engine's speed range. The result is responsive acceleration needed for situations like merging or passing on a highway, but in a manner that is more efficient.

The Duramax 3.0L Turbo-Diesel even provides plenty of power and strength right off the line, reaching 95 percent of peak torque at a low 1,250 rpm. Possessing a max towing† capability of 9,100 lbs. and a max payload of 1,830 lbs. for four-wheel models, all of that low-end torque allows you to pull heavy loads, maximizing your fuel economy during towing events.

And by pairing the Duramax 3.0L Turbo-Diesel with the 10-speed automatic transmission, drivers will notice smooth gear changes. This not only enhances its efficiency, but adds refinement to the driving experience.

If that wasn't enough, the transmission works in combination with the engine's exhaust braking capability when you are in Tow/Haul mode. By leveraging the diesel engine's compression to help slow the vehicle, the transmission and exhaust brake not only reduce brake pad wear, but give truck owners more confidence and control while trailering on steep grades.



When it comes to capability, the Duramax 3.0L Turbo-Diesel is no slouch to taking on the work week or weekend adventure, offering powerful torque even at low RPMs and a segment-leading 277 diesel horsepower.


277 HP    460 LB-FT  3.23   9,1001,830


By reaching 95 percent of peak torque at a low 1,250 rpm and full torque from 1,500-3,000 rpm, the Duramax 3.0L Turbo-Diesel provides excellent power and momentum without exerting the engine while taking on trails or roads in hilly or mountainous regions.

It also lends itself well to the formidable off-road capability of the Sierra AT4, giving you plenty of low-end torque to keep moving through rough trails and rugged terrain, especially at low speeds. Combining distinctive premium style, advanced technology and off-road capability in a full-sized pickup truck, the Sierra AT4 features a factory-installed 2-inch suspension lift for ground clearance while heading off-road.


While anyone familiar with a diesel engine can recognize the audible sounds they make, the Duramax 3.0L Turbo-Diesel takes advantage of its inline-six architecture to be as quiet as it is smooth.

Compared to a DOHC V6 engine, an I-6 configuration offers the ideal balance of primary and secondary forces because only two camshafts and their associated valvetrain components are operating at one time. This not only eliminates the need for using balancing shafts, but minimizes friction.

And by including additional noise and vibration canceling features, such as a tuned air induction system, truck owners will enjoy an exceptionally quiet and smooth experience at any engine speed.


When it comes to capability, truck owners want the ability to tow or haul†, as well as modern conveniences to help make it easier. And when the Duramax 3.0L Turbo-Diesel is combined with standard or available technologies, truck owners can take advantage of advanced features designed to make their experience easier and give them more confidence.

These technologies include:

Traction Select System: Drivers can select from preset drive modes tailored for different terrain or weather conditions, including Tow/Haul. Designed for trailering or carrying a large payload†, Tow/Haul modifies the transmission calibration so shift points are higher and the engine is able to deliver peak power. It also maximizes performance by allowing for a more responsive accelerator pedal calibration while disabling start/stop functionality. And if the truck is turned off, it will remain in Tow/Haul mode up to four hours. This eliminates the need for owners to reengage Tow/Haul when making stops shorter than four hours.

ProGrade Trailering System†: Offering connectivity and convenience, the available ProGrade Trailering System goes beyond a basic towing package with invaluable tools to help make drivers feel more confident while trailering, taking the experience to another level. This system includes an In-Vehicle Trailering App and integrated cameras.

Class-Leading 15 Camera Views†: Allowing you to monitor your truck and trailer, these available 15 different camera views can be accessed through the infotainment system† screen and can remain visible even while the vehicle is in motion. The views include the industry-first transparent trailer view†, which uses the tailgate-mounted camera and an available auxiliary accessory camera mounted on the rear of the trailer (customer installed) to create a view where the driver virtually "sees through" the trailer. Transparent trailer view works with compatible box or camping trailers up to 32 feet in length using a conventional hitch.

*Class is half-ton pickup segment.
**Before you buy a vehicle or use it for trailering, carefully review the trailering section of the Owner's Manual. The weight of passengers, cargo and options or accessories may reduce the amount you can tow.
***App functionality and features vary with vehicle equipment and trim level. Data connection may be required. Some features require active service plan and working electrical system. User terms and limitations apply.
****Read the vehicle Owner's Manual for important feature limitations and information. Some camera views require available accessory camera and installation. Not compatible with all trailers. See your dealer for details.
*****Functionality varies by model. Full functionality requires compatible Bluetooth and smartphone, and USB connectivity for some devices.
******Requires available accessory trailer camera and installation. Not compatible with all trailers. See your dealer for details. Read the vehicle's owner's manual for important feature limitations and information.