GM Duramax Engines

Duramax is a series of turbo-diesel engines produced by General Motors for use in pickup trucks, SUVs and vans.

First introduced in 2001, Duramax engines range from four, six and eight cylinders in inline (I) or V configurations.

Produced Duramax Engines

A total of 11 Duramax engines have been produced since 2001 globally, including:

6.6L V-8 LB7
6.6L V-8 LLY
6.6L V-8 LBZ
6.6L V-8 LMM
6.6L V-8 LGH
6.6L V-8 LML
6.6L V-8 L5P
2.5L I-4 XLD25
2.8L I-4 XLD28
2.8L I-4 LWN
3.0L I-6 LM2

GM Duramax Turbo Diesel Engines

Engine RPO Code	Year In Production	Displacement (L / ci)	Layout & Cylinders	Valvetrain	Aspiration	Compression Ratio	Bore & Stroke (in / mm)	Fuel	Fuel Delivery	Engine Block Material	Cylinder Head Material	Power (hp / kW @ RPM)	Torque (lb-ft / Nm @ RPM)	Chevrolet Applications	GMC Applications	Other Applications
LB7	2001 - 2004	6.6 / 402.7	V-8	OHV, 4 valves per cylinder	Turbocharged & Intercooled	17.5:1	4.06 x 3.90 / 103 x 99	Diesel	Direct injection, high pressure common-rail	Cast Iron	Aluminum	300 / 223.7 @ 3,100	520 / 705 @ 1,800	Kodiak, Silverado HD	Topkick, Sierra HD
LLY	2004 - 2005	6.6 / 402.7	V-8	OHV, 4 valves per cylinder	Turbocharged & Intercooled	17.5:1	4.06 x 3.90 / 103 x 99	Diesel	Direct injection, high pressure common-rail	Cast gray iron	Cast aluminum	305 / 227 @ 3000	605 / 820 @ 1600	Silverado HD	Sierra HD	Hummer H1 Alpha
LLY/LBZ	2006 - 2007	6.6 / 402.7	V-8	OHV, 4 valves per cylinder	Turbocharged & Intercooled	16.8:1	4.06 x 3.90 / 103 x 99	Diesel	Direct injection, high pressure common-rail	Cast gray iron	Cast aluminum	250 - 360 / 190 - 270 @3200	460 - 650 / 624 - 881 @1600	Kodiak, Silverado HD, Express	Topkick, Sierra, Savanna
LMM	2007 - 2010	6.6 / 402.7	V-8	OHV, 4 valves per cylinder	Turbocharged & Intercooled	16.8:1	4.06 x 3.90 / 103 x 99	Diesel	Direct injection, high pressure common-rail	Cast gray iron	Cast aluminum	250 - 365 / 190 - 272 @3200	460 - 660 / 624 - 895 @1600	Kodiak, Silverado HD, Express	Topkick, Sierra HD, Savanna
LGH	2010 - 2017	6.6 / 402.7	V-8	OHV, 4 valves per cylinder	Turbocharged & Intercooled	16.0:1	4.06 x 3.90 / 103 x 99	Diesel	Direct injection, high pressure common-rail	Cast iron	Cast aluminum	260 - 335 / 194 - 250 @ 3100	525 - 685 / 712 - 929 @ 1600	Silverado HD, Express	Sierra HD, Savanna
LML	2011 - 2016	6.6 / 402.7	V-8	OHV, 4 valves per cylinder	Turbocharged & Intercooled	16.0:1	4.06 x 3.90 / 103 x 99	Diesel	Direct injection, high pressure common-rail	Cast iron	Cast aluminum	397 / 294 @ 3000	765 / 1037 @ 1600	Silverado HD	Sierra HD
XLD25	2011 - Present	2.5 / 152.5	I-4	DOHC, 4 valves per cylinder	Turbocharged	16.5:1	3.62 x 3.7 / 92 x 94	Diesel	Direct injection, high pressure common-rail	Cast iron	Cast aluminum	163 / 120 @ 3600	280 / 38- @ 2000	Colorado/S-10, TrailBlazer (International Markets)
XLD28	2012 - Present	2.8 / 170.8	I-4	DOHC, 4 valves per cylinder	Turbocharged	16.5:1	3.7 x 3.9 / 94 x 100	Diesel	Direct injection, high pressure common-rail	Cast iron	Cast aluminum	200 / 147 @ 3600	360 / 500 @ 2000	Colorado/S-10, TrailBlazer (International Markets)
LWN	2014 - Present	2.8 / 170.8	I-4	DOHC, 4 valves per cylinder	Turbocharged	16.5:1	3.7 x 3.9 / 94 x 100	Diesel	Direct injection, high pressure common-rail	Cast grey iron	Cast aluminum	181 / 135 @ 3400	369 / 500 / @ 2000	Colorado	Canyon
L5P	2017 - Present	6.6 / 402.7	V-8	OHV, 4 valves per cylinder	Turbocharged & Intercooled	16.0:1	4.06 x 3.90 / 103 x 99	Diesel	Direct injection, high pressure common-rail	Cast iron	Cast aluminum	445 / 331.8 @ 2,800	910 / 1233.8 @ 1,600	Silverado HD	Sierra HD
LM2	2019 - Present	3.0 / 183	I-6	DOHC, 4 valves per cylinder	Turbocharged	TBD	TBD	Diesel	Direct injection, high pressure common-rail	Cast iron	Cast aluminum	TBD	TBD	Silverado 1500	Sierra 1500
LMK	Never produced	4.5 / 274.6	V-8	OHV, 4 valves per cylinder	Turbocharged	Unknown	Unknown	Diesel	Direct injection, high pressure common-rail	Unknown	Unknown	310 / 231 @ TBD	520 / 705 @ TBD	Not produced, but planned for Silverado 1500	Not produced, but planned for Sierra 1500

Not Produced Duramax Engines

From what we know, one Duramax engine was developed but was never put into production.

Developed entirely in-house by GM and assigned RPO Code LMK, the engine displaced 4.5 liters from a V8 layout. It was report to have been rated at 310 horsepower and 520 pound-feet of torque while meeting all modern emissions requirements. The motor, sometimes referred to as Baby Duramax, was slated to be offered in GM’s light duty pickup trucks – the Chevrolet Silverado 1500 and GMC Sierra 1500 – for the 2010 model year.

However, after fully completing development of the engine, GM decided not to produce it due to reasons associated with the “economic climate”. After that, the automaker considered several times to put the 4.5L Duramax into production, but never did. Instead, it developed two new small-displacement Duramax engines – the 2.8L I4 LWN (XLD28 in international markets) and the 3.0L I6 LM2.