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GM 6.6 Liter L5D V-8 Duramax Turbo Diesel Engine

The GM L5D Duramax is a turbo-diesel engine produced by General Motors for use in its new Medium Duty Class 4, 5 and 6 trucks. Displacing 6.6 liters in a V-8 configuration, the L5D is part of a new generation of Duramax engines.

6.6L L5D Engine Vitals
Displacement: 6.6L / 403 cu. in.
Aspiration: Natural
Vehicles: Chevrolet Silverado MD and HD, GMC Sierra MD and HD
Introduced: 2019 model year
Discontinued:
Predecessor: L5P Duramax V8
Successor:
Assembly: Moraine, Ohio, USA

The GM L5D engine made its debut in the 2019 Chevrolet Silverado Medium Duty trucks – the Silverado 4500HD, Silverado 5500HD, and Silverado 6500HD. It produces an estimated 700 pound-feet of torque and 350 horsepower.

The engine is closely related to the 6.6L Duramax V-8 L5P engine, but with a smaller turbo and a different tune. Chevrolet has told us that the L5D has “minor differences” from the L5P.

L5D specifications are currently not available, so we are providing specs for the closely-related L5P until we have more information on the L5D.

GM 6.6L L5P V-8 Duramax Turbo Diesel Engine Specs
Type 6.6L V-8 Turbo-Diesel
GM RPO Code L5P
Displacement 403 ci
Compression Ratio 16.0:1
Valve Configuration Overhead
Valves Per Cylinder 4
Assembly Site Moraine, Ohio, USA
Valve Lifters Mechanical roller
Firing Order 1 – 2 – 7 – 8 – 4 – 5 – 6 – 3
Bore x Stroke 103 x 99 mm
Fuel System Direct injection with high-pressure common rail
Fuel Type Ultra-low-sulfur diesel and B20 biodiesel
Maximum Powered Speed 3450 rpm
Maximum Braking Speed 4800 rpm
Emissions Controls Cooled Exhaust Gas Recirculation (EGR), Selective Catalytic Reduction (SCR), Diesel Particulate Filter (DPF), intake throttle
Block Cast iron
Cylinder Head Cast aluminum
Intake Manifold Cast aluminum
Exhaust Manifold Cast nodular iron with steel pipe extension
Main Bearing Caps Cast nodular iron
Crankshaft Forged steel
Camshaft Steel
Connecting Rods PM iron
Engine Oil Capacity 10 qt./9.5L
GM 6.6L L5D V-8 Duramax Turbo Diesel Engine Vehicle Applications
Vehicle Transmission Power (hp / kW) @ RPM Torque (lb-ft / Nm) @ RPM
2019 Chevrolet Silverado 4500HD and newer Allison Transmission (model TBD) 350 / 261 @ 2700 700 / 516 @ 1600
2019 Chevrolet Silverado 5500HD and newer Allison Transmission (model TBD) 350 / 261 @ 2700 700 / 516 @ 1600
2019 Chevrolet Silverado 6500HD and newer Allison Transmission (model TBD) 350 / 261 @ 2700 700 / 516 @ 1600
2019 International Trucks (model TBD) and newer Allison Transmission (model TBD) 350 / 261 @ 2700 700 / 516 @ 1600

The 6.6L Duramax L5D engine is manufactured at the GM Duramax plant in Moraine, Ohio, USA.

Follow our Duramax L5D news coverage.

GM L5D engine pictures coming soon.

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