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6.6L LML Duramax Specifications and Information

LML Duramax Specs, Background, and information.

LML Duramax Specs, Background, And Information

2014 Chevrolet Silverado 3500HD LML Duramax
Chevolet Silverado 3500 HD LT Crew Cab Pickup

The LML Duramax began in 2011, and followed the LMM Duramax Engine. Increased emissions regulations resulted in the need for GM to produce an engine that was both cleaner and more powerful. LML Duramax trucks added 30 horsepower and 100 lb-ft of torque over the LMM. The LML Duramax engine is actually the longest used Duramax engine in the segment so far, as it was used between 2011-2016. According to Chevrolet, the LML boasted 11% better fuel economy over the previous generation Duramax as well. A lot had to change to accomplish better performance, fuel economy, and lower emissions. Check out our chart below for all the LML Duramax specifications you NEED to know.

LML Duramax Specifications Chart

Manufactured Years:2011-2016
Engine Design: 6.6L 90-Degree V8 Turbocharged Diesel
Transmission:6-Speed Allison Transmission
VIN Identification:
(8th Digit of VIN)
Displacement:403 Cubic Inches or 6.6 Liters
Bore:4.055″ or 103 MM
Stroke:3.897″ or 99 mm
Block Material:Cast Iron Block
Cylinder Head Material:Aluminum
Intake Manifold:Cast Aluminum
Crankshaft:Forged Steel, Nitride Hardened
Connecting Rods:Forged Steel
Compression Ratio:16.0:1
Firing Order:1-2-7-8-4-5-6-3
Turbocharger/Air:Garrett GT3788VA Variable Vane
Turbocharger (VVT)
Fuel Injection:Bosch High Pressure Common Rail
with CP4.2 injection pump and
Piezoelectric Injectors
Valvetrain:32 Valve (OHV) Overhead Valve Design,
4 valves per cylinder
Engine Oil Capacity:10 Quarts with Filter or 9.5 Liters
DEF Fluid Capacity:5 Gallons
Cooling System Capacity:25.4 quarts or 24 Liters
Fuel:B20 Biodiesel Blend or Ultra Low Sulfur Diesel
Fuel Tank Size:36 Gallons Standard
Max Engine Speed:3450
Max Braking Speed:4800
Horsepower:397 horsepower at 3,000 RPM
Torque:765 Lb/Ft at 1,600 RPM

LML Duramax Information

Early LML Duramax trucks share many exterior characteristics of the LMM. The same overall body-style was retained with minor changes including a louvered hood, new front bumpers, and grilles. Another exterior change is the addition of a DEF tank (Diesel exhaust fluid) found underneath the truck. The placement of the DEF tank is an eye sore on both early body-style and late body-style LML trucks. Even early L5P Duramax trucks share the same issue.

In 2015, the LML Duramax was given a major exterior overhaul. A new cabin giving rear passengers an added 2″ of leg room was used, as well as a new bed available in 6’6″ or 8′ sizes. The new beds featured ez-lift and lowering tailgates as well as integrated CornerSteps into the rear bumper to make getting in and out of the truck easier. The entire trucks were made using high-strength steel and the frames were strengthened to increase payloads and maximum tow capacity. The Chevrolet MyLink entertainment system was introduced, featuring a new 7″ touch screen head-unit. These new LML Duramax trucks also gained a new six-gauge instrument cluster along with a new driver information center.

LML Duramax Performance

Chevrolet Silverado 2500 HD LTZ Crew Cab Pickup

The LML Duramax shocked its rivals when it was revealed, offering 397 horsepower and 765 lb-ft of torque while simultaneously lowering emissions and improving fuel economy. A new, improved engine block casting was used. GM increased oil film thickness by changing the main bearings’ profiles. For superior lubrication and cooling, a new oil pump was introduced with greater flow, to increase pressures at slower speeds. Duramax trucks also gained an exhaust brake for the first time ever using variation of the Garrett G3788VA Variable Vane Turbo. Bosch supplied a new fuel injection system, featuring a CP4.2 pump and Piezoelectric injectors. This new fuel system actually caused a lot of issues for LML Duramax owners. Find our full list of LML Duramax problems and solutions by clicking here.

Other improvements to the LML Duramax platform include a lighter and stronger piston and connecting rod design that allow for high horsepower and torque applications. The braking system was greatly improved in the LML trucks over the 2010 LMM Duramax. Larger, 14″ rotors were used, as well as stronger calipers to help with the increased capacities and tow ratings on these trucks. Larger wheel hubs and bearing assemblies were also used. Steering improvements were also made to support the higher gross front axle weight rating and improve handling and feel on the road.

LML Duramax Emissions

To meet stricter emissions standards, GM incorporated an SCR (Selective Catalyst Reduction) system as well as a “9th injector” design upgrade to the DPF system. These were used in conjunction with the existing EGR (Exhaust Gas Recirculation) and EGR Cooler systems. An EGR bypass system was also used to reduce high-mileage soot deposits in both the EGR Cooler and EGR circuits. These new emissions devices accomplished an emissions reduction of up to 63%. For more details about LML Duramax Emissions specifications, click here.

Tow Ratings & Capacities

LML Duramax Towing Specifications & Capacities
2015 Silverado 3500HD LML Duramax

Tow ratings and capacities are different in the years of the LML Duramax. They depend on which body-style LML you have. Just like any truck, your cab configuration, whether your truck is a dually or not, and numerous other factors also have an impact on tow ratings and capacities. Here is a basic chart we created with LML Duramax towing specifications. For full Duramax specs by year, visit the Chevrolet website.

LML Silverado 2500HD & Sierra 2500HD Towing

Max 5th
Wheel Tow:
2011-201413,000 lbs17,500 lbs10,000 lbs3,431 lbs
2015-201614,500 lbs18,000 lbs10,000 lbs3,275 lbs

LML Silverado 3500HD & Sierra 3500HD Towing

Max 5th
Wheel Tow:
Dually: 18,000 lbs
Dually: 22,500 lbs
5,740 lbs
SRW: 15,000 lbs
Dually: 20,000 lbs
SRW: 17,500 lbs
Dually: 23,200 lbs
5,587 lbs

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