The Chevrolet Silverado 2500 HD II, specifically the Regular Cab Long Box configuration powered by the 6.6-liter Duramax turbodiesel V8 engine paired with an Allison automatic transmission, represents a significant iteration in Chevrolet’s heavy-duty truck lineage. Produced from 2007 through 2010 (GMT900 platform), this variant was aimed squarely at buyers needing substantial towing and hauling capability, particularly in the American market where heavy-duty trucks are a mainstay for both work and personal use. This model year saw substantial updates to the Silverado HD line, focusing on increased power, improved refinement, and enhanced durability compared to its predecessors.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD II (GMT900) Regular Cab Long Box |
| Type (Engine) | 6.6 Duramax TD V8 (365 Hp) Automatic |
| Start of production | 2007 |
| End of production | 2010 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 2 |
| Doors | 2 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 7.5 kg/Hp, 134.2 Hp/tonne |
| Weight-to-torque ratio | 3 kg/Nm, 329 Nm/tonne |
| Power | 365 Hp @ 3200 rpm |
| Power per litre | 55.3 Hp/l |
| Torque | 895 Nm @ 1600 rpm (660.12 lb.-ft. @ 1600 rpm) |
| Maximum engine speed | 3450 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Duramax LMM |
| 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 | 16.8:1 |
| 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 | 2720 kg (5996.57 lbs.) |
| Max. weight | 4173 kg (9199.89 lbs.) |
| Max load | 1453 kg (3203.32 lbs.) |
| Trunk (boot) space – maximum | 2138 l (75.5 cu. ft.) |
| Fuel tank capacity | 129 l (34.08 US gal | 28.38 UK gal) |
| Permitted trailer load with brakes (12%) | 5897 kg (13000.66 lbs.) |
| Length | 5708 mm (224.72 in.) |
| Width including mirrors | 2032 mm (80 in.) |
| Height | 1939 mm (76.34 in.) |
| Wheelbase | 3378 mm (132.99 in.) |
| Front track | 1744 mm (68.66 in.) |
| Rear (Back) track | 1676 mm (65.98 in.) |
| Ride height (ground clearance) | 243 mm (9.57 in.) |
| Minimum turning circle (turning diameter) | 13.8 m (45.28 ft.) |
| Drivetrain Architecture | Rear wheel drive. Internal Combustion engine. |
| 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, 325×38 mm |
| Rear brakes | Ventilated discs, 325×30 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Tires size | 245/75 R16; 265/75 R17 |
| Wheel rims size | 6.5J x 16; 7.5J x 17 |
INTRODUCTION
The 2007-2010 Chevrolet Silverado 2500 HD II with the 6.6L Duramax and Allison automatic was a workhorse designed for demanding tasks. Positioned as a mid-to-high range offering within the 2500 HD lineup, it sat above the gasoline-powered variants but below specialized configurations like those geared towards commercial fleets. The GMT900 platform represented a significant overhaul of the Silverado HD series, focusing on increased capability and a more refined driving experience. The Regular Cab Long Box configuration was popular with those prioritizing cargo space and towing capacity over passenger comfort.
Powertrain & Engine Architecture
At the heart of this Silverado 2500 HD lies the Duramax LMM 6.6-liter V8 turbodiesel engine. This engine is a significant evolution of the previous LBZ Duramax, featuring a redesigned combustion chamber and improved fuel injection system. The LMM utilizes a common-rail direct injection system, delivering fuel at extremely high pressures for optimized combustion efficiency and reduced emissions. The engine produces 365 horsepower at 3200 rpm and a robust 895 lb-ft of torque at 1600 rpm. The valvetrain employs an overhead valve (OHV) configuration, known for its simplicity and durability. The engine is longitudinally mounted in the chassis.
The Allison 1000 six-speed automatic transmission is a crucial component of this powertrain. Known for its strength and reliability, the Allison transmission is specifically designed to handle the high torque output of the Duramax engine. The transmission features a lock-up torque converter for improved fuel efficiency at highway speeds. Gear ratios are optimized for both towing and everyday driving, providing a balance between power and economy.
Driving Characteristics
The Silverado 2500 HD 6.6L Duramax Automatic delivers a driving experience focused on capability rather than outright speed. While the 365 horsepower is adequate, the true strength lies in the massive 895 lb-ft of torque. This translates to effortless towing and hauling, even with substantial loads. Acceleration is brisk, but the truck’s weight is always apparent. Compared to the gasoline-powered Silverado 2500 HD models, the Duramax offers significantly more low-end torque, making it far superior for demanding tasks. Compared to manual transmission equipped Duramax models, the automatic provides a more relaxed driving experience, particularly in stop-and-go traffic, but may sacrifice some control and fuel efficiency. The Allison transmission shifts smoothly and decisively, contributing to a refined driving experience for a heavy-duty truck.
Equipment & Trim Levels
The Silverado 2500 HD II in this configuration typically came standard with features like air conditioning, power windows and locks, and a basic audio system. The interior upholstery was typically vinyl or cloth, reflecting the truck’s work-oriented nature. Optional extras included leather upholstery, a premium audio system, navigation, and various towing packages. Trim levels varied, but this configuration often fell into the LT or Work Truck trims, offering a balance of features and affordability. The Regular Cab configuration prioritized interior space for two occupants and a large, usable cargo bed.
Chassis & Braking
The Silverado 2500 HD II features a robust chassis designed to withstand heavy loads. The front suspension utilizes an independent torsion bar and double wishbone setup, providing a comfortable ride and good handling. The rear suspension employs a traditional leaf spring design, known for its durability and load-carrying capacity. Braking duties are handled by ventilated disc brakes on all four wheels, with ABS (Anti-lock Braking System) as standard equipment. The rear brakes are slightly smaller in diameter than the front brakes. The steering system utilizes a cone worm with recirculation balls, providing a solid and predictable steering feel.
Market Reception & Comparison
The 2007-2010 Silverado 2500 HD with the Duramax/Allison combination was generally well-received by critics and consumers alike. It was praised for its impressive towing and hauling capabilities, refined ride quality, and durable powertrain. Fuel economy, while not a primary concern for buyers in this segment, was considered acceptable for a heavy-duty truck. Compared to the gasoline-powered Silverado 2500 HD models, the Duramax offered significantly better fuel economy when towing heavy loads. Compared to competitors like the Ford Super Duty and Ram 2500, the Silverado 2500 HD was often seen as a strong contender, offering a compelling combination of power, refinement, and reliability.
Legacy
The Duramax LMM engine and Allison transmission pairing in the Silverado 2500 HD II have proven to be exceptionally durable and reliable. These trucks continue to be popular in the used car market, commanding relatively high prices due to their reputation for longevity and capability. Properly maintained examples can easily exceed 200,000 miles. While some maintenance items, such as the fuel injectors and turbocharger, can be costly to repair, the overall reliability of the powertrain is excellent. The GMT900 platform Silverado 2500 HD remains a popular choice for those needing a capable and dependable heavy-duty truck.
