Technical Specifications
| Brand | GMC |
| Model | Sierra 2500HD |
| Generation | Sierra 2500HD III (GMT900) Regular Cab Long Box |
| Type (Engine) | 6.0 V8 (360 Hp) 4WD Automatic |
| Start of production | 2007 |
| End of production | 2010 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 2 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 7 kg/Hp, 142.9 Hp/tonne |
| Weight-to-torque ratio | 4.9 kg/Nm, 204.4 Nm/tonne |
| Power | 360 Hp @ 5400 rpm |
| Power per litre | 60.3 Hp/l |
| Torque | 515 Nm @ 4200 rpm, 379.84 lb.-ft. @ 4200 rpm |
| Maximum engine speed | 6000 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Vortec LY6 |
| Engine displacement | 5967 cm3, 364.13 cu. in. |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 101.6 mm, 4 in. |
| Piston Stroke | 92 mm, 3.62 in. |
| Compression ratio | 9.6:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV |
| Engine oil capacity | 5.7 l, 6.02 US qt | 5.02 UK qt |
| Coolant | 15.5 l, 16.38 US qt | 13.64 UK qt |
| Kerb Weight | 2520 kg, 5555.65 lbs. |
| Max. weight | 4173 kg, 9199.89 lbs. |
| Max load | 1653 kg, 3644.24 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%) | 5761 kg, 12700.83 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 | The Internal combustion engine (ICE) drives the rear wheels permanently, and the front wheels are driven through an electrically or mechanically operated clutch if necessary. |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 6 gears, automatic transmission Hydra-Matic |
| 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 |
The GMC Sierra 2500HD III, produced between 2007 and 2010, represented the third generation of GMC’s heavy-duty truck line. Built on the GMT900 platform, this generation saw significant improvements in towing capacity, interior refinement, and overall robustness compared to its predecessors. The Regular Cab Long Box configuration, coupled with the 6.0-liter Vortec LY6 V8 engine and a four-speed automatic transmission, was a popular choice for customers needing a capable work truck without the added cost of diesel power or more luxurious trim levels. This combination prioritized functionality and affordability, making it a common sight on job sites and farms across the United States.
Powertrain & Engine Architecture
At the heart of this Sierra 2500HD variant lies the Vortec LY6 6.0-liter V8 engine. This engine is a member of the Vortec family, known for its robust construction and relatively simple design. The LY6 features a cast iron block and aluminum cylinder heads, contributing to its durability. It utilizes a multi-port fuel injection system, delivering fuel directly to each cylinder for efficient combustion. The overhead valve (OHV) valvetrain, while not as technologically advanced as overhead cam designs, is known for its reliability and ease of maintenance. The engine produces 360 horsepower at 5400 rpm and 515 Nm (379.84 lb-ft) of torque at 4200 rpm.
The engine is mated to a four-speed Hydra-Matic automatic transmission. While not offering the gear ratios of more modern transmissions, the Hydra-Matic was a proven and durable unit capable of handling the engine’s torque output. The transmission’s gear ratios were optimized for towing and hauling, providing adequate power delivery in most situations. The 4WD system employed a traditional transfer case, allowing the driver to switch between two-wheel drive, four-wheel drive high, and four-wheel drive low for enhanced traction in various conditions.
Driving Characteristics
The 6.0-liter V8 and four-speed automatic combination in the Sierra 2500HD delivered a driving experience focused on capability rather than outright performance. Acceleration was adequate for everyday driving, but the truck’s substantial weight limited its responsiveness. The automatic transmission shifted smoothly, but lacked the refinement of newer transmissions with more gears. When towing, the engine demonstrated its strength, providing ample torque to pull heavy loads. However, the limited number of gears meant the engine often operated at higher rpm levels, resulting in increased noise and fuel consumption. Compared to the available Duramax diesel engine, this variant offered less torque and lower fuel economy, but at a significantly lower purchase price.
Equipment & Trim Levels
The Regular Cab Long Box 6.0L V8 4WD Sierra 2500HD typically came with a fairly basic level of equipment. Standard features included air conditioning, a basic audio system, and vinyl upholstery. The interior was functional and durable, designed to withstand the rigors of work truck use. Optional extras included power windows and locks, upgraded audio systems, and a towing package. The exterior featured a black plastic grille and bumpers, reflecting its work-oriented nature. Higher trim levels, such as the SLT, offered more luxurious features like leather upholstery, woodgrain trim, and premium audio systems, but were not typically paired with the base 6.0L engine.
Chassis & Braking
The Sierra 2500HD’s chassis was designed for heavy-duty use. It featured a fully boxed frame for increased rigidity and strength. The front suspension utilized an independent torsion bar setup with double wishbone components, providing a comfortable ride while maintaining good handling characteristics. The rear suspension employed a traditional leaf spring setup, capable of supporting heavy loads. Braking duties were handled by ventilated disc brakes on all four wheels, providing adequate stopping power for the truck’s weight. An anti-lock braking system (ABS) was standard, enhancing safety during emergency braking situations.
Market Reception & Comparison
The 6.0-liter V8-powered Sierra 2500HD was generally well-received by critics and consumers alike. It was praised for its robust engine, capable towing capacity, and affordable price. However, it was often criticized for its relatively low fuel economy compared to diesel alternatives. Compared to the 6.6-liter Duramax diesel engine, the 6.0L V8 offered significantly less torque and fuel efficiency, but it was also considerably cheaper to purchase and maintain. The 4.8L V8 models were even more affordable, but lacked the power needed for serious towing or hauling.
Legacy
The GMT900-generation Sierra 2500HD, including the 6.0-liter V8 variant, has proven to be a durable and reliable truck. The Vortec LY6 engine is known for its longevity, and with proper maintenance, can easily exceed 200,000 miles. The four-speed Hydra-Matic transmission is also relatively reliable, although it may require occasional servicing. Today, these trucks are readily available on the used car market at affordable prices, making them a popular choice for buyers seeking a capable and dependable work truck. While not as fuel-efficient or technologically advanced as newer trucks, the Sierra 2500HD remains a testament to GMC’s commitment to building tough and reliable vehicles.
