The Chevrolet Silverado 2500HD II, specifically the facelifted version produced from 2011 to 2014, represented a significant evolution in Chevrolet’s heavy-duty truck lineup. This iteration, built on the GMT900 platform, offered a robust combination of power, capability, and refinement aimed at the demanding needs of American truck buyers. The Extended Cab Long Box configuration, paired with the 6.6-liter Duramax turbodiesel V8 engine producing 397 horsepower and 765 lb-ft of torque, and a six-speed Allison automatic transmission, positioned this variant as a workhorse capable of serious towing and hauling. It sat towards the upper end of the 2500HD trim levels, appealing to those needing substantial capability without necessarily opting for the fully-loaded 3500HD models.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD II (GMT900, facelift 2011) Extended Cab Long Box |
| Type (Engine) | 6.6 Duramax TD V8 (397 Hp) 4WD Automatic |
| Start of production | 2011 |
| End of production | 2014 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 2 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 8.3 kg/Hp, 120.3 Hp/tonne |
| Weight-to-torque ratio | 3.2 kg/Nm, 314.2 Nm/tonne |
| Power | 397 Hp @ 3000 rpm |
| Power per litre | 60.2 Hp/l |
| Torque | 1037 Nm @ 1600 rpm (764.85 lb.-ft. @ 1600 rpm) |
| Maximum engine speed | 3000 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Duramax LML |
| Engine displacement | 6599 cm3 (402.7 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 103 mm (4.06 in.) |
| Piston Stroke | 99 mm (3.9 in.) |
| Compression ratio | 16:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | OHV |
| Engine oil capacity | 9.5 l (10.04 US qt | 8.36 UK qt) |
| Coolant | 24 l (25.36 US qt | 21.12 UK qt) |
| Kerb Weight | 3300 kg (7275.25 lbs.) |
| Max. weight | 4536 kg (10000.17 lbs.) |
| Max load | 1236 kg (2724.91 lbs.) |
| Trunk (boot) space – maximum | 2138 l (75.5 cu. ft.) |
| Fuel tank capacity | 136 l (35.93 US gal | 29.92 UK gal) |
| Permitted trailer load with brakes (12%) | 5897 kg (13000.66 lbs.) |
| Length | 6337 mm (249.49 in.) |
| Width including mirrors | 2032 mm (80 in.) |
| Height | 1971 mm (77.6 in.) |
| Wheelbase | 4018 mm (158.19 in.) |
| Front track | 1748 mm (68.82 in.) |
| Rear (Back) track | 1709 mm (67.28 in.) |
| Ride height (ground clearance) | 214 mm (8.43 in.) |
| Minimum turning circle (turning diameter) | 15.8 m (51.84 ft.) |
| Drivetrain Architecture | All wheel drive (4×4). ICE drives rear wheels, front wheels engaged via clutch. |
| Number of gears and type of gearbox | 6 gears, automatic transmission Allison |
| Front suspension | Independent torsion bar, double wishbone |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Ventilated discs, 350×40 mm |
| Rear brakes | Ventilated discs, 360×34 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Tires size | 245/75 R17; 265/70 R17; 265/70 R18; 265/60 R20 |
| Wheel rims size | 7.5J x 17; 8J x 18; 8.5J x 20 |
INTRODUCTION
The 2011-2014 Chevrolet Silverado 2500HD II, in its Extended Cab Long Box configuration with the 6.6L Duramax diesel and Allison automatic, was a key player in the competitive American heavy-duty truck market. Following the GMT800 series, the GMT900 platform brought improvements in interior refinement, towing capacity, and overall durability. This particular variant aimed to balance capability with a degree of everyday usability, making it a popular choice for both commercial users and individuals needing a powerful truck for work and recreation. The facelift in 2011 brought updated styling cues and further refinements to the already capable platform.
Powertrain & Engine Architecture
At the heart of this Silverado 2500HD lies the Duramax LML 6.6-liter V8 turbodiesel engine. This engine is a testament to diesel engineering, featuring a cast iron block, aluminum cylinder heads, and a robust rotating assembly. The LML generation of the Duramax introduced a revised combustion chamber design and a cooled exhaust gas recirculation (EGR) system to further reduce emissions. Fuel is delivered via a high-pressure common rail diesel injection system, ensuring precise fuel metering for optimal combustion and power delivery. The engine utilizes an overhead valve (OHV) valvetrain, a design choice favored for its durability and simplicity. A variable geometry turbocharger and intercooler work in tandem to maximize power and torque across the engine’s operating range. The Allison 1000 six-speed automatic transmission is specifically designed to handle the immense torque output of the Duramax engine. It features a lock-up torque converter for improved fuel efficiency and a heavy-duty cooling system to prevent overheating under demanding conditions.
Driving Characteristics
The 397 horsepower and 765 lb-ft of torque produced by this combination translate into impressive real-world performance. While not as overtly quick as some gasoline-powered trucks, the Duramax/Allison pairing delivers a broad, flat torque curve, making it exceptionally capable for towing and hauling heavy loads. The Allison transmission is well-programmed, providing smooth and decisive shifts. Compared to the standard gasoline engines or even the higher-output Duramax variants, this configuration prioritizes usability and fuel economy. The 6-speed Allison transmission provides a good balance of gear ratios, allowing for comfortable highway cruising and sufficient grunt for off-road situations. The weight of the truck and the inherent characteristics of a diesel engine mean that throttle response isn’t instantaneous, but the sheer pulling power more than compensates for this.
Equipment & Trim Levels
The Extended Cab Long Box 2500HD typically came standard with features like air conditioning, power windows and locks, a basic audio system, and vinyl upholstery. However, this configuration was often upgraded with popular options packages. Leather upholstery, heated front seats, a premium audio system, navigation, and a rear vision camera were commonly added. The interior design, while functional, wasn’t overly luxurious, focusing instead on durability and ease of use. Exterior features included chrome bumpers and grille accents, and available options included power-adjustable mirrors and running boards.
Chassis & Braking
The Silverado 2500HD features a fully boxed frame for exceptional strength and rigidity. The front suspension utilizes an independent torsion bar setup with double wishbone control arms, providing a comfortable ride and good handling. The rear suspension employs a traditional leaf spring design, optimized for load-carrying capacity. Braking duties are handled by ventilated disc brakes at all four corners, providing ample stopping power even when towing heavy loads. An Anti-lock Braking System (ABS) is standard. The truck’s robust chassis and suspension components are designed to withstand the stresses of heavy-duty use.
Market Reception & Comparison
The 2011-2014 Silverado 2500HD with the Duramax/Allison combination received generally positive reviews. Critics praised its towing capacity, comfortable ride (for a heavy-duty truck), and the reliability of the Duramax engine. Compared to the gasoline-powered Silverado 2500HD models, the diesel offered significantly better fuel economy when towing and a much higher towing capacity. Against competitors like the Ford Super Duty and Ram 2500, the Silverado 2500HD held its own, often being lauded for its refined Allison transmission and strong diesel engine. However, some critics noted that the interior wasn’t as luxurious as some of its rivals.
Legacy
The Duramax LML engine and Allison 1000 transmission have proven to be exceptionally durable powertrains. Well-maintained examples of this Silverado 2500HD continue to command respectable prices on the used market. The engine is known for its longevity, often exceeding 200,000 miles with proper care. Common maintenance items include regular oil changes, fuel filter replacements, and coolant flushes. The availability of aftermarket performance upgrades allows owners to further enhance the truck’s capabilities. This generation of Silverado 2500HD remains a popular choice for those seeking a capable and reliable heavy-duty truck.
