The Chevrolet Silverado 2500HD II, specifically the Crew Cab Long Box configuration powered by the 6.6-liter Duramax turbodiesel V8 and paired with an Allison automatic transmission, represents a significant iteration of Chevrolet’s heavy-duty pickup truck lineage. Produced from 2011 to 2014 as part of the GMT900 platform’s facelift, this variant aimed to deliver substantial towing and hauling capability alongside a degree of comfort and refinement expected in a crew cab pickup. It occupied a premium position within the Silverado 2500HD lineup, catering to owners requiring serious work capacity without sacrificing everyday usability.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD II (GMT900, facelift 2011) Crew Cab Long Box |
| Type (Engine) | 6.6 Duramax TD V8 (397 Hp) Automatic |
| Start of production | 2011 |
| End of production | 2014 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 8.1 kg/Hp, 123.8 Hp/tonne |
| Weight-to-torque ratio | 3.1 kg/Nm, 323.5 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 | 3206 kg (7068.02 lbs.) |
| Max. weight | 4536 kg (10000.17 lbs.) |
| Max load | 1330 kg (2932.15 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 | 6581 mm (259.09 in.) |
| Width including mirrors | 2032 mm (80 in.) |
| Height | 1984 mm (78.11 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) | 211 mm (8.31 in.) |
| Minimum turning circle (turning diameter) | 16.7 m (54.79 ft.) |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| 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 |
Powertrain & Engine Architecture
The heart of this Silverado 2500HD variant is the Duramax LML 6.6-liter V8 turbodiesel engine. This engine represented a significant evolution of the Duramax design, incorporating a redesigned combustion chamber, improved fuel injection strategies, and a more robust cooling system. The LML utilized a common-rail direct injection system, delivering fuel at extremely high pressures for optimized combustion efficiency and reduced emissions. The engine featured an overhead valve (OHV) valvetrain, a design choice favored for its durability and packaging advantages in a truck application. A variable geometry turbocharger and intercooler further enhanced performance and reduced turbo lag. The Allison 6-speed automatic transmission, known for its durability and smooth shifting, was specifically calibrated to handle the high torque output of the Duramax engine. This transmission featured a lock-up torque converter for improved fuel efficiency at highway speeds.
Driving Characteristics
The 6.6L Duramax with the Allison automatic provided a compelling blend of power and usability. While not as overtly quick as gasoline-powered trucks, the Silverado 2500HD delivered prodigious torque from low engine speeds, making it exceptionally capable for towing and hauling heavy loads. The Allison transmission’s gear ratios were optimized for both work and highway cruising. The automatic transmission, while convenient, did result in a slight reduction in fuel economy compared to the available manual transmission. The overall driving experience was characterized by a comfortable ride, thanks to the torsion bar front suspension and leaf spring rear suspension, although the ride could become somewhat stiff when the bed was unloaded.
Equipment & Trim Levels
The Crew Cab Long Box configuration was typically offered in LT and LTZ trim levels. The LT trim included standard features such as air conditioning, power windows and locks, a basic audio system, and cloth upholstery. The LTZ trim added features like leather upholstery, heated front seats, a premium audio system, and additional chrome exterior trim. Optional extras included a navigation system, a rear-seat entertainment system, and various towing packages. The interior design was functional and durable, prioritizing practicality over luxury.
Chassis & Braking
The Silverado 2500HD II featured a robust chassis designed to withstand the stresses of heavy-duty use. The front suspension utilized an independent torsion bar setup with double wishbone components, providing a comfortable ride and good handling. The rear suspension employed a traditional leaf spring design, offering excellent load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, providing ample stopping power even when towing heavy loads. An Anti-lock Braking System (ABS) was standard equipment. The truck’s substantial weight and long wheelbase contributed to its stability and predictable handling.
Market Reception & Comparison
The 2011-2014 Silverado 2500HD with the Duramax/Allison combination received generally positive reviews. Critics praised its powerful engine, smooth-shifting transmission, and impressive towing capacity. Compared to the gasoline-powered Silverado 2500HD models, the Duramax diesel offered significantly better fuel economy when towing and a much higher torque output. Compared to competitors like the Ford Super Duty and Ram 2500, the Silverado 2500HD was often seen as a well-rounded offering, balancing capability, comfort, and reliability. However, some reviewers noted that the interior design was somewhat dated compared to newer competitors.
Legacy
The Duramax LML engine and Allison transmission pairing proved to be exceptionally durable and reliable. These trucks have maintained strong resale values in the used car market, particularly those that have been well-maintained. The LML Duramax is known for its longevity and ability to withstand high mileage. While diesel engines generally require more expensive maintenance than gasoline engines (e.g., diesel exhaust fluid refills, potential for injector issues), the Duramax LML has earned a reputation for being a relatively trouble-free engine. Today, these Silverado 2500HDs remain popular choices for owners who need a capable and reliable heavy-duty pickup truck.
