3.0L Duramax Diesel LM2

While GM was the last to deliver a diesel engine option to the 1/2 ton market, they've done so in style. The 3.0L Duramax I-6 joins the list of available engines for the 2020 Chevrolet Silverado/GMC Sierra 1500. The segment exclusive inline 6 offers up to 277 horsepower and 460 lb-ft of torque while earning an EPA rated 33 mpg on the highway for two wheel drive configurations and 29 mpg for four wheel drive models. The engine actively competes with Ram's 3.0L EcoDiesel V-6 and Fords 3.0L Power Stroke V-6, found in Ram 1500 and F-150 models, respectively.

3.0L Duramax I-6 Diesel Specs & Information

While the new 3.0L Duramax has yet to be proven, it's a technological revelation with a great deal of innovative, unique, and never-before-seen features. The cast aluminum engine block offers significant weight savings, but utilizes iron cylinder liners for more robust wear protection and reliability. The deep skirt engine block design places the bottom of the engine block well below the centerline of the crankshaft and utilizes a lower crankcase extension attached to the main bearing caps (often referred to as a girdle) for added rigidity and strength. Hypereutectic aluminum pistons and forged steel connecting rods transmit power to the forged steel crankshaft, which is secured in place by a total of 7 nodular iron main bearing caps.

The 3.0L Duramax is rated up to 277 horsepower at 3,750 RPM and 460 ft-lbs of torque at 1,500 RPM. Furthermore, GM claims the engine produces 90% of peak torque by 1,250 RPM (414 lb-ft) and maintains peak torque from 1,500 to 3,000 RPM, giving the engine a relatively broad torque curve. At just over 5,000 RPM, the Duramax features a remarkably high max engine speed for a diesel engine (and more particularly, an inline engine).

Active thermal management is amongst the unique features of the 3.0L Duramax, which employs a series of 3 electronically actuated valves in the engine cooling system to manage the distribution of coolant through the engine block. By targeting specific coolant pathways, engine warm-up times are reduced and an ideal engine operating temperature is maintained under grueling ambient conditions. Ceramic glow plugs promise quick engine starting and GM suggests that the engine block heater is only necessary when temperatures drop below - 22° F.

An electronically variable intake manifold effectively shortens/lengthens intake runners via flap valves to perpetually optimize airflow based on operating conditions. While this technique does not necessarily have a major role in overall power development, it significantly contributes to providing a broad torque curve and general engine responsiveness.

The 3.0L Duramax utilizes the 10L80 ten speed automatic transmission, which was co-developed with Ford Motor Company (Ford designation 10R80). Like the Ford variant, the 10L80 features automatic start-stop technology designed to shut down the engine once the vehicle is brought to a complete stop and promptly restart the engine when takeoff is desired.

3.0L Duramax Engine Specs


3.0L Duramax diesel

GM RPO Code::


Vin Code:


Assembly Location:

Flint Engine Plant, Flint, Michigan


2020 - current Chevrolet Silverado 1500
2020 - current GMC Sierra 1500
2021 - current Cadillac Escalade
2021 - current Chevrolet Tahoe
2021 - current Chevrolet Suburban
2021 - current GMC Yukon


Inline 6 (I-6)


182.6 CID, 2.99 liters


3.307 in (84 mm)


3.543 in (90 mm)

Bore/Stroke Ratio:

0.93 (undersquare)

Firing Order:

1 - 5 - 3 - 6 - 2 - 4

3.0L Duramax cylinder numbers

Engine Block Material:

Cast aluminum w/ iron cylinder liners

Cylinder Head Material:

Aluminum alloy

Compression Ratio:

15.0 : 1

Injection System:

Direct injection
Denso high pressure common rail, 36,250 psi max injection pressure
Chain driven, twin piston high pressure injection pump
Solenoid-type fuel injectors with 9 hole nozzles
Up to 10 injection events per combustion cycle


Turbocharged, intercooled
Single ball bearing, liquid cooled variable geometry turbocharger (VGT)
Water-to-air charge air cooler (intercooler)
Integrated exhaust brake
42.8 psi peak manifold pressure (absolute) [1]


Dual overhead camshafts (DOHC), chain driven
4 valves per cylinder (24 valve)
Maintenance-free finger followers with hydraulic lash adjusters
1.12 inch (28.35 mm) intake valves
0.97 inch (24.55 mm) exhaust valves
Variable flow intake manifold

Reciprocating Assembly:

Hypereutectic cast aluminum pistons
Forged steel crankshaft
Steel camshafts
Forged steel connecting rods
Nodular iron main bearing caps


Ultra-low sulfur diesel, maximum B20 biodiesel blend

Engine Oil Capacity:

7.0 quarts w/ filter change

Engine Oil Spec:

SAE 0W-20 DexosD diesel engine oil


277 hp @ 3,750 rpm


460 lb-ft @ 1,500 rpm

Max Engine Speed:

5,000 rpm (electronically governed)

Fuel Economy [2]:

2WD config:

23 mpg city, 33 mpg hwy, 27 mpg combined

4WD config:

23 mpg city, 29 mpg hwy, 25 mpg combined

Engine Dimensions:


35.75 inches (908 mm)


35.98 inches (914 mm)


35.55 inches (903 mm)

Engine Weight:

467 lbs

[1] 42.8 psi absolute pressure; converts to approximately 28 psi gauge pressure at sea level.
[2] Fuel economy based on 2021 model year Chevrolet Silverado/GMC Sierra 1500 models.

3.0L Duramax Horsepower & Torque Curve

3.0L Duramax diesel horsepower and torque graph

3.0L Duramax Horsepower and Torque Graph

Page Information

Last update: 12/10/2021

Copyright: Diesel Hub (dieselhub.com), all rights reserved

Source(s): GM press releases, Silverado/Sierra brochures, factory spec sheet, owners manuals, 3.0L Duramax diesel supplement, and vehicle configuration guides (gmpowertrain.com, gmc.com, chevrolet.com, and in print form)