The GMC Sierra 3500HD III, specifically the Extended Cab Long Box configuration with the 6.0-liter V8 engine and four-wheel drive, represents a significant iteration in GMC’s heavy-duty truck lineage. Produced from 2011 to 2013 as part of the GMT900 platform’s facelift, this variant was aimed squarely at the American market’s demand for capable and powerful work trucks. It slotted into the Sierra 3500HD lineup as a robust offering, positioned above the base models but below the more specialized or diesel-powered trims. This truck was designed for owners needing substantial towing and payload capacity without sacrificing everyday usability.
Technical Specifications
| Brand | GMC |
| Model | Sierra 3500HD |
| Generation | Sierra 3500HD III (GMT900, facelift 2011) Extended Cab Long Box |
| Type (Engine) | 6.0 V8 (360 Hp) 4WD DRW Automatic |
| Start of production | 2011 |
| End of production | 2013 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 8.8 kg/Hp, 114.1 Hp/tonne |
| Weight-to-torque ratio | 6.1 kg/Nm, 163.2 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 | 3156 kg, 6957.79 lbs. |
| Max. weight | 5908 kg, 13024.91 lbs. |
| Max load | 2752 kg, 6067.12 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%) | 6078 kg, 13399.7 lbs. |
| Length | 6337 mm, 249.49 in. |
| Width including mirrors | 2436 mm, 95.91 in. |
| Height | 1966 mm, 77.4 in. |
| Wheelbase | 4018 mm, 158.19 in. |
| Front track | 1748 mm, 68.82 in. |
| Rear (Back) track | 1906 mm, 75.04 in. |
| Ride height (ground clearance) | 213 mm, 8.39 in. |
| Minimum turning circle (turning diameter) | 16.1 m, 52.82 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, 355×40 mm |
| Rear brakes | Ventilated discs, 373×34 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Tires size | 235/80 R17; 265/70 R18 |
Powertrain & Engine Architecture
At the heart of this Sierra 3500HD variant lies the Vortec L96 6.0-liter V8 engine. This engine, a staple of GM’s truck lineup for many years, is a cast-iron block, overhead valve (OHV) design. It utilizes a multi-port fuel injection system for precise fuel delivery and features variable valve timing (VVT) to optimize performance and efficiency across the rev range. The L96 produces 360 horsepower at 5400 rpm and 515 Nm (379.84 lb-ft) of torque at 4200 rpm. The engine’s longitudinal mounting and robust construction were key to its ability to handle the demands of heavy towing and hauling. Paired with the engine is the Hydra-Matic 6-speed automatic transmission, known for its durability and smooth shifting. This transmission was specifically tuned for truck applications, providing appropriate gear ratios for both work and highway driving.
Driving Characteristics
The 6.0-liter V8 and 6-speed automatic combination in the Sierra 3500HD offered a balance between power and usability. While not as quick as some of the lighter-duty pickups, it provided ample torque for towing substantial loads and navigating challenging terrain. The automatic transmission, while not offering the driver control of a manual, provided smooth and predictable shifts. Compared to the available diesel options, this gasoline engine was noticeably less fuel-efficient, but it offered a lower initial purchase price and a quieter, smoother driving experience. The gear ratios were optimized for towing, with lower gears providing strong pulling power and higher gears allowing for comfortable highway cruising. The four-wheel-drive system added further capability, enabling confident traction in adverse weather conditions or off-road situations.
Equipment & Trim Levels
The Extended Cab Long Box 6.0L 4WD configuration typically came standard with features geared towards work and utility. These included air conditioning, a basic audio system, vinyl upholstery, and power windows and locks. The extended cab provided additional interior space compared to the regular cab models, offering more room for passengers or storage. Optional extras included upgraded audio systems, leather upholstery, power-adjustable seats, and a navigation system. The exterior typically featured chrome accents and durable paint finishes designed to withstand the rigors of work-truck life. The Long Box bed provided a generous cargo capacity, making it ideal for hauling large items.
Chassis & Braking
The Sierra 3500HD’s chassis was built for durability and heavy-duty use. It featured a fully boxed frame constructed from high-strength steel. The front suspension utilized an independent torsion bar setup with double wishbones, providing a comfortable ride and good handling. The rear suspension employed a traditional leaf spring design, optimized for load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, providing ample stopping power even when heavily loaded. An Anti-lock Braking System (ABS) was standard, enhancing safety and control. The rear axle was a heavy-duty unit designed to withstand the stresses of towing and hauling.
Market Reception & Comparison
The 2011-2013 GMC Sierra 3500HD with the 6.0-liter V8 and automatic transmission received generally positive reviews. Critics praised its robust construction, ample power, and comfortable ride. However, fuel economy was a common criticism, as the gasoline engine consumed significantly more fuel than the available diesel options. Compared to the Duramax diesel variants, this 6.0L model was seen as a more affordable option for those who didn’t require the ultimate in towing capacity or fuel efficiency. It appealed to owners who primarily used their trucks for occasional towing or hauling and valued the lower purchase price and quieter operation of the gasoline engine.
Legacy
The Vortec L96 6.0-liter V8, when paired with the Hydra-Matic transmission, has proven to be a relatively reliable powertrain. While not without its potential issues (such as Active Fuel Management system problems in some cases), it generally holds up well over time with proper maintenance. In the used car market, these Sierra 3500HD models remain popular choices for those seeking a capable and affordable heavy-duty truck. Their robust construction and readily available parts contribute to their longevity and ease of maintenance. The combination of gasoline power and four-wheel drive continues to appeal to buyers who prioritize simplicity and value over ultimate fuel economy.
