6.6L Duramax LGH

The 6.6L Duramax LGH is a de-rated version of the Duramax LML introduced for the 2011 model year for chassis cab and box-delete trucks (RPO code ZW9) in addition to the GMC Savana and Chevrolet Express model lines. For the 2013 model year, chassis cab trucks received the more powerful LML, but the LGH remained available in Express/Savana vans through the 2016 model year. In addition to have a less powerful engine calibration, the LGH employs a smaller Garrett variable geometry turbocharger than the LML.

6.6L LGH Duramax Engine Specs & Information

For 2011 to 2012 chassis cab applications, the LGH is rated at 335 horsepower and 685 lb-ft of torque; power is transmitted through the Allison 1000 six speed automatic transmission just as it is in pickup truck models equipped with the LML Duramax. For 2011 to 2016 commercial van applications, the LGH is rated at a much lower 260 horsepower and 525 lb-ft of torque. Express/Savana van applications employ the GM 6L90E six speed automatic transmission in lieu of the brawny Allison 1000.

6.6L LGH Duramax Specs

Engine Family:

6.6L Duramax diesel (Duramax 6600)

RPO Code:


VIN Code:


Assembly Site:

DMAX engine plant, Moraine, Ohio

Applications/Production Years:

2011 - 2016 Chevrolet Express 2500, 3500, 4500 vans
2011 - 2016 GMC Savana 2500, 3500, 4500 vans
2011 - 2012 Chevrolet Silverado 3500 HD chassis cab
2011 - 2012 GMC Sierra 3500 HD chassis cab


6.599 liters (6.6 liters nominal), 402.62 CID (403 CID nominal)


90 degree V-8

B10 Life:

Not specified

B50 Life:

Not specified


4.055 inches (103.00 mm)


3.897 inches (99.00 mm)

Bore/Stroke Ratio:

1.04 (marginally oversquare)

Compression Ratio:

16.0 : 1

Firing Order:


Cylinder Numbers:

6.6 Duramax cylinder numbers and locations

Cylinders 1, 3, 5, and 7 are located on the passenger side bank
Cylinders 2, 4, 6, and 8 are located on the driver side bank

Engine Block Material:

Cast gray iron

Cylinder Head Material:

Cast aluminum alloy

Injection System:

Direct injection
Bosch high pressure common rail system
Piezoelectric fuel injectors
Bosch CP4.2 injection pump


Turbocharged, air-to-air intercooler
Garrett GT3582VA variable geometry turbocharger (VGT)


Overhead valve (OHV), standard cam-in-block, mechanical roller lifters
4 valves per cylinder (32 valve)

Cold Start Aid(s):

Traditional glow plug system, 1 per cylinder

Engine Oil Capacity:

10 quarts with oil filter change

Lube Oil Filter P/N:

ACDelco PF2232


Ultra low sulfur diesel (ULSD) or max B20 biodiesel blend

Peak Horsepower:

Express/Savana Vans

260 hp @ 3,100 rpm

Silverado/Sierra chassis cab

335 hp @ 3,100 rpm

Peak Torque:

Express/Savana Vans

525 lb-ft @ 1,600 rpm

Silverado/Sierra chassis cab

685 lb-ft @ 1,600 rpm

Idle Speed:

~ 680 rpm @ operating temperature

Governed Speed:

3,450 rpm (electronically governed)

Emissions Equipment:

Selective catalytic reduction (SCR, requires diesel exhaust fluid), diesel particulate filter (DPF), diesel oxidation catalyst (DOC), exhaust gas recirculation (EGR) w/ single EGR cooler

Coupled Transmissions:

Allison 1000 6 speed automatic (chassis cabs), GM 6L90E 6 speed automatic (vans)

Engine Weight:

Approx. 835 lbs

Engine Dimensions:


Approx 30.0 inches


Approx 30.0 inches


Approx 32.0 inches

6.6L LGH Duramax Horsepower & Torque Curves

LGH Duramax horsepower and torque curves

6.6L Duramax LGH horsepower and torque curves for Savana/Express van models