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 aimed to balance robust capability with a degree of everyday usability. Positioned as a mid-to-upper tier offering within the 3500HD range, it catered to buyers needing substantial towing and payload capacity without necessarily opting for the diesel-powered models. This truck was primarily sold in the North American market, where demand for heavy-duty pickups remained consistently strong.
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 SRW 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 | 8.9 kg/Hp, 112.6 Hp/tonne |
| Weight-to-torque ratio | 6.2 kg/Nm, 161 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 | 3198 kg, 7050.38 lbs. |
| Max. weight | 4990 kg, 11001.07 lbs. |
| Max load | 1792 kg, 3950.68 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%) | 6169 kg, 13600.32 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 | 1709 mm, 67.28 in. |
| Ride height (ground clearance) | 213 mm, 8.39 in. |
| Minimum turning circle (turning diameter) | 15.8 m, 51.84 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 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 employs multi-port fuel injection for precise fuel delivery. The overhead valve (OHV) valvetrain, while not as sophisticated as overhead cam designs, is known for its reliability and ease of maintenance. Variable Valve Timing (VVT) was incorporated to improve fuel efficiency and low-end torque. The engine produces 360 horsepower at 5400 rpm and 515 Nm (379.84 lb-ft) of torque at 4200 rpm. The Hydra-Matic 6L80E six-speed automatic transmission was the standard pairing for this engine. This transmission offered smooth shifting and helped optimize the engine’s powerband for both towing and daily driving.
Driving Characteristics
The 6.0L V8 and 6L80E automatic combination delivered a capable, if not particularly sporty, driving experience. While lacking the prodigious torque of the Duramax diesel, the gasoline engine provided ample power for most hauling tasks. The automatic transmission’s gear ratios were tuned for towing, resulting in relatively conservative gearing. Acceleration was adequate, but the truck’s substantial weight (approximately 7,050 lbs) limited its responsiveness. Compared to the manual transmission equipped versions, the automatic offered greater convenience, especially in stop-and-go traffic. However, it did result in a slight reduction in fuel economy and a less direct connection to the powertrain. The 4WD system provided enhanced traction in inclement weather and off-road conditions, making it a versatile choice for owners who needed to navigate challenging terrain.
Equipment & Trim Levels
The 2011-2013 Sierra 3500HD Extended Cab Long Box 6.0L 4WD typically came standard with features like air conditioning, power windows and locks, a basic audio system, and vinyl upholstery. Extended Cab models offered a second row of seating, albeit somewhat cramped. Popular optional extras included upgraded audio systems with navigation, leather upholstery, heated seats, a power sunroof, and various towing packages. Trim levels varied, but generally included Work Truck (WT), LT, and LTZ. The LT trim added features like chrome exterior accents, upgraded interior materials, and additional convenience items. The LTZ represented the highest level of luxury, offering premium leather interiors, advanced audio systems, and a host of other amenities.
Chassis & Braking
The Sierra 3500HD’s chassis was designed for heavy-duty use. It featured a fully boxed frame for enhanced rigidity and durability. 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 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 equipment. The rear axle was a solid axle, typical for heavy-duty trucks, and was designed to withstand significant stress.
Market Reception & Comparison
Critics generally praised the GMC Sierra 3500HD for its robust construction, towing capacity, and comfortable ride. However, the 6.0L V8 engine was often seen as a compromise compared to the more powerful and fuel-efficient Duramax diesel. Fuel economy was a common criticism, with the gasoline engine returning significantly lower MPG figures than the diesel counterpart. Compared to the 6.6L Duramax diesel, the 6.0L offered lower initial cost but higher long-term operating expenses due to fuel consumption. The 6.0L also provided less torque, making it less ideal for extremely heavy towing applications. However, the 6.0L engine was generally considered more reliable and less prone to expensive repairs than the Duramax.
Legacy
The 2011-2013 GMC Sierra 3500HD with the 6.0L V8 and 6L80E automatic transmission remains a popular choice in the used truck market. The Vortec L96 engine is known for its durability and relatively simple maintenance requirements. While not as fuel-efficient as newer trucks, it offers a reliable and capable powertrain for those needing a heavy-duty pickup. These trucks are often sought after by owners who prioritize affordability and simplicity over the complexity of modern diesel engines. With proper maintenance, these trucks can provide many years of reliable service, making them a solid value in the used truck market.
