The GMC Sierra 2500HD IV (GMTK2XX) Double Cab Long Box, equipped with the 6.0-liter V8 engine and automatic transmission, represents a significant iteration in GMC’s heavy-duty truck lineage. Produced from 2015 to 2019, this variant occupied a sweet spot in the 2500HD lineup, offering a balance of capability, comfort, and affordability for buyers needing serious towing and hauling capacity without the premium price tag of higher trim levels or diesel engines. It was a mainstay for both commercial users and individuals requiring a robust pickup for work and recreational purposes within the North American market.
Technical Specifications
| Brand | GMC |
| Model | Sierra 2500HD |
| Generation | Sierra 2500HD IV (GMTK2XX) Double Cab Long Box |
| Type (Engine) | 6.0 V8 (360 Hp) Automatic |
| Start of production | 2015 |
| End of production | 2019 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 7.8 kg/Hp, 128 Hp/tonne |
| Weight-to-torque ratio | 5.5 kg/Nm, 183.1 Nm/tonne |
| Power | 360 Hp @ 5400 rpm |
| Power per litre | 60.4 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 | 5965 cm3, 364.01 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 | 16.1 l, 17.01 US qt | 14.17 UK qt |
| Kerb Weight | 2812 kg, 6199.4 lbs. |
| Max. weight | 4309 kg, 9499.72 lbs. |
| Max load | 1497 kg, 3300.32 lbs. |
| Trunk (boot) space – maximum | 2162 l, 76.35 cu. ft. |
| Fuel tank capacity | 136 l, 35.93 US gal | 29.92 UK gal |
| Permitted trailer load with brakes (12%) | 6532 kg, 14400.59 lbs. |
| Length | 6322 mm, 248.9 in. |
| Width including mirrors | 2045 mm, 80.51 in. |
| Height | 1978 mm, 77.87 in. |
| Wheelbase | 4017 mm, 158.15 in. |
| Front track | 1748 mm, 68.82 in. |
| Rear (Back) track | 1709 mm, 67.28 in. |
| Ride height (ground clearance) | 216 mm, 8.5 in. |
| Minimum turning circle (turning diameter) | 16.2 m, 53.15 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 | Coil spring, Double wishbone, Transverse stabilizer |
| 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 | 245/75R17; 265/70R17; 265/70R18; 265/60 R20 |
| Wheel rims size | 7.5J x 17; 8J x 18; 8.5J x 20 |
INTRODUCTION
The 2015-2019 GMC Sierra 2500HD Double Cab Long Box with the 6.0L V8 and automatic transmission was a key component of the GMTK2XX platform, representing the fourth generation of GMC’s heavy-duty truck series. This generation brought significant improvements in interior refinement, technology, and overall capability compared to its predecessors. The Double Cab configuration offered a spacious interior for passengers, while the Long Box provided ample cargo space. This particular variant was positioned as a workhorse, appealing to buyers who needed substantial towing and payload capacity but didn’t necessarily require the higher cost and complexity of a diesel engine.
Powertrain & Engine Architecture
At the heart of this Sierra 2500HD lies the Vortec L96 6.0-liter V8 engine. This engine is a member of the Vortec family, known for its robust construction and reliable performance. The L96 features a cast iron block, aluminum cylinder heads, and a two-valve-per-cylinder overhead valve (OHV) valvetrain with variable valve timing (VVT) for improved efficiency and low-end torque. Fuel delivery is handled by a multi-port fuel injection system. The engine produces 360 horsepower at 5400 rpm and 515 lb-ft of torque at 4200 rpm. The engine is longitudinally mounted, sending power to the rear wheels. Paired with the L96 is the Hydra-Matic 6L80 six-speed automatic transmission. This transmission is known for its durability and smooth shifting characteristics. The 6L80 features electronically controlled shifting and overdrive for improved fuel economy at highway speeds.
Driving Characteristics
The 6.0L V8 and 6L80 automatic combination delivers a capable, if not exhilarating, driving experience. While not as quick as some of the lighter-duty pickups or those equipped with more powerful engines, the Sierra 2500HD provides ample power for towing and hauling heavy loads. The automatic transmission is well-tuned, offering smooth and predictable shifts. The gear ratios are optimized for towing, providing strong low-end torque. Compared to the available diesel engines, the 6.0L V8 is noticeably quieter and smoother, but it lacks the diesel’s superior torque output and fuel efficiency. Manual transmission options were available on other trims, offering more driver control, but the automatic was favored by many for its ease of use, especially when towing.
Equipment & Trim Levels
The 2500HD Double Cab Long Box 6.0L Automatic typically came standard with features such as air conditioning, power windows and locks, a basic audio system, and vinyl upholstery. Higher trim levels, such as SLE and SLT, added features like leather upholstery, heated seats, a premium audio system, navigation, and a rearview camera. Optional extras included a trailer brake controller, a locking rear differential, and various appearance packages. The Double Cab configuration provided comfortable seating for five passengers, making it a practical choice for families or crews.
Chassis & Braking
The Sierra 2500HD features a robust chassis designed to handle heavy loads. The front suspension utilizes coil springs and a double wishbone design with a transverse stabilizer bar. The rear suspension employs a traditional leaf spring setup. Braking duties are handled by ventilated disc brakes on all four wheels, with ABS (Anti-lock Braking System) standard. The rear brakes are slightly larger (360x34mm) than the front (350x40mm) to accommodate the increased weight and braking demands. Steering is accomplished via a cone worm with recirculation balls system.
Market Reception & Comparison
The 6.0L V8-equipped Sierra 2500HD received generally positive reviews. Critics praised its strong towing capacity, comfortable ride, and user-friendly features. However, some noted that its fuel economy was lower than that of the diesel models. Compared to the 6.6L Duramax diesel, the 6.0L V8 offered a lower initial cost but sacrificed fuel efficiency and ultimate towing capacity. The 6.0L also proved to be more reliable than some earlier iterations of the Duramax, reducing long-term maintenance concerns for some buyers.
Legacy
The GMTK2XX Sierra 2500HD with the 6.0L V8 and 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 the most fuel-efficient option, it provides a reliable and capable powertrain for those needing a heavy-duty truck. These trucks continue to be sought after by individuals and businesses alike, offering a compelling combination of capability, affordability, and longevity. Common issues reported include oil consumption and occasional sensor failures, but overall, the powertrain is considered robust and dependable.
