The GMC Sierra 2500HD III, specifically the Extended Cab Standard Box configuration with the 6.0-liter V8 engine and automatic transmission, represents a significant iteration in GMC’s heavy-duty truck lineage. Produced from 2011 to 2014 as part of the GMT900 platform’s facelift, this variant aimed to balance robust capability with a degree of everyday usability. It occupied a middle ground within the 2500HD lineup, offering more power and towing capacity than the base models, but remaining more accessible than the diesel-powered options. This truck was primarily targeted at American buyers needing a powerful workhorse for hauling and towing, whether for commercial purposes or personal use.
Technical Specifications
| Brand | GMC |
| Model | Sierra 2500HD |
| Generation | Sierra 2500HD III (GMT900, facelift 2011) Extended Cab Standard Box |
| Type (Engine) | 6.0 V8 (360 Hp) Automatic |
| Start of production | 2011 |
| End of production | 2014 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 7.6 kg/Hp, 131.7 Hp/tonne |
| Weight-to-torque ratio | 5.3 kg/Nm, 188.4 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 L96 |
| 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, VVT |
| 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 | 2734 kg, 6027.44 lbs. |
| Max. weight | 4309 kg, 9499.72 lbs. |
| Max load | 1575 kg, 3472.28 lbs. |
| Trunk (boot) space – maximum | 1718 l, 60.67 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 | 5857 mm, 230.59 in. |
| Width including mirrors | 2032 mm, 80 in. |
| Height | 1979 mm, 77.91 in. |
| Wheelbase | 3663 mm, 144.21 in. |
| Front track | 1748 mm, 68.82 in. |
| Rear (Back) track | 1709 mm, 67.28 in. |
| Ride height (ground clearance) | 218 mm, 8.58 in. |
| Minimum turning circle (turning diameter) | 14.6 m, 47.9 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 Hydra-Matic |
| 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
At the heart of this Sierra 2500HD variant lies the Vortec L96 engine, a 6.0-liter (364 cubic inches) V8. This engine is a member of the Vortec family, known for its robust construction and relatively simple design. The L96 utilizes a cast iron block and aluminum cylinder heads, contributing to its durability. It features a 9.6:1 compression ratio and a multi-port fuel injection system, delivering a respectable 360 horsepower at 5400 rpm and 515 Nm (379.84 lb-ft) of torque at 4200 rpm. The engine employs an overhead valve (OHV) valvetrain with variable valve timing (VVT) to optimize performance and efficiency. The Hydra-Matic 6-speed automatic transmission was the sole transmission option for this configuration. This transmission is known for its smooth shifting and reliability, although it isn’t as fuel-efficient as some newer automatic transmissions.
Driving Characteristics
The 6.0L V8 and 6-speed automatic combination provided a solid, if not spectacular, driving experience. While not as quick as some of the lighter-duty trucks, the Sierra 2500HD offered ample power for towing and hauling heavy loads. The automatic transmission’s gear ratios were tuned for work, prioritizing low-end torque over outright acceleration. Compared to the available diesel options, this gasoline engine was noticeably less fuel-efficient, especially when towing. However, it offered a smoother and quieter driving experience, and the initial purchase price was lower. The truck’s substantial weight and heavy-duty suspension meant that the ride quality was firm, even when unloaded.
Equipment & Trim Levels
The Extended Cab Standard Box 6.0L configuration typically came with a reasonable level of standard equipment. This included air conditioning, power windows and locks, a basic audio system, and vinyl upholstery. Higher trim levels, such as the LT and SLT, added features like leather upholstery, upgraded audio systems, heated seats, and a navigation system. Optional extras included a trailer brake controller, a locking rear differential, and various appearance packages. The extended cab provided additional storage space behind the front seats, making it a practical choice for those needing occasional passenger space or secure storage.
Chassis & Braking
The Sierra 2500HD’s chassis was built for heavy-duty work. It featured a fully boxed frame and a robust suspension system. The front suspension utilized an independent torsion bar setup with double wishbones, while the rear suspension employed a traditional leaf spring design. This configuration provided a good balance of ride comfort and load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, with ABS as standard. The truck’s substantial weight required a powerful braking system to ensure safe stopping distances.
Market Reception & Comparison
The 6.0L V8-powered Sierra 2500HD was generally well-received by critics and buyers alike. It was praised for its strong towing capacity, comfortable interior, and relatively affordable price. However, its fuel economy was a common criticism, especially compared to the diesel options. Compared to the Duramax diesel engine, the 6.0L V8 offered less torque and lower fuel efficiency, but it was significantly cheaper to purchase and maintain. The gasoline engine also lacked the diesel’s long-term durability and resale value.
Legacy
The GMT900-generation Sierra 2500HD, including the 6.0L V8 automatic variant, has proven to be a relatively reliable truck. The Vortec L96 engine is known for its durability, and the Hydra-Matic transmission is generally dependable. However, like any vehicle, these trucks are susceptible to age-related issues, such as rust and wear and tear on suspension components. In the used car market, these trucks remain popular among those seeking a capable and affordable heavy-duty pickup. While the diesel models command a higher price, the 6.0L V8 variant offers a compelling value proposition for buyers who don’t require the ultimate in towing capacity or fuel efficiency.


