The GMC Sierra 2500HD IV (GMTK2XX) Double Cab Long Box, equipped with the 6.0-liter V8 engine producing 360 horsepower and paired with a 4WD automatic transmission, was a mainstay of GMC’s heavy-duty truck lineup from 2015 to 2019. This configuration represented a sweet spot for many buyers seeking a capable work truck with a degree of comfort and refinement. Positioned within the fourth generation of the Sierra HD series, it offered a balance between towing capacity, payload, and everyday usability, appealing to both commercial users and private owners needing substantial hauling capabilities.
Technical Specifications
| Brand | GMC |
| Model | Sierra 2500HD |
| Generation | Sierra 2500HD IV (GMTK2XX) Double Cab Long Box |
| Type (Engine) | 6.0 V8 (360 Hp) 4WD 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 | 8.2 kg/Hp, 122.3 Hp/tonne |
| Weight-to-torque ratio | 5.7 kg/Nm, 175 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 | 2943 kg, 6488.2 lbs. |
| Max. weight | 4309 kg, 9499.72 lbs. |
| Max load | 1366 kg, 3011.51 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%) | 6396 kg, 14100.77 lbs. |
| Length | 6322 mm, 248.9 in. |
| Width including mirrors | 2045 mm, 80.51 in. |
| Height | 1977 mm, 77.83 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) | 214 mm, 8.43 in. |
| Minimum turning circle (turning diameter) | 16.2 m, 53.15 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 | 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 | 245/75 R17; 265/70 R17; 265/70 R18; 265/60 R20 |
| Wheel rims size | 7.5J x 17; 8J x 18; 8.5 J x 20 |
Powertrain & Engine Architecture
At the heart of this Sierra 2500HD variant lies the Vortec L96 6.0-liter V8 engine. This engine, a member of GM’s Vortec family, is a cast-iron block, aluminum-head design known for its durability and relatively simple architecture. It utilizes a traditional overhead valve (OHV) valvetrain with variable valve timing (VVT) to optimize performance and efficiency. Fuel delivery is managed by a multi-port fuel injection system, providing precise fuel metering for consistent power output. The engine produces 360 horsepower at 5400 rpm and 515 lb-ft of torque at 4200 rpm, making it well-suited for heavy-duty tasks. The Hydra-Matic 6L90 six-speed automatic transmission was the standard pairing for this engine. This transmission is known for its robustness and smooth shifting characteristics, providing adequate gear ratios for both towing and everyday driving. The 6L90 features electronically controlled shifting and a tow/haul mode that optimizes shift points for improved control when hauling heavy loads.
Driving Characteristics
The 6.0L V8 and 6L90 automatic combination in the Sierra 2500HD delivered a capable, if not particularly sporty, driving experience. While not as quick as some of the lighter-duty pickups or those equipped with the optional Duramax diesel engine, the 6.0L provided ample power for accelerating with moderate loads or maintaining highway speeds. The automatic transmission’s gear ratios were well-suited for towing, providing strong low-end torque and minimizing the need for frequent downshifts. Compared to the manual transmission options, 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 engine. The ride quality, typical of heavy-duty trucks, was firm but reasonably comfortable, especially with the Double Cab configuration’s longer wheelbase.
Equipment & Trim Levels
The Double Cab Long Box configuration of the Sierra 2500HD typically came standard with features like air conditioning, power windows and locks, a basic audio system, and vinyl upholstery. Higher trim levels, such as the SLT and Denali, added features like leather upholstery, heated and ventilated front seats, a premium audio system, navigation, and a host of convenience features. Optional extras included a sunroof, rear-seat entertainment system, and various towing packages. The specific equipment level varied depending on the chosen trim package and individual options selected by the buyer.
Chassis & Braking
The Sierra 2500HD IV featured a robust chassis designed to handle heavy loads. The front suspension utilized a coil spring, double wishbone setup with a transverse stabilizer bar, while the rear suspension employed a traditional leaf spring configuration. This setup provided a good balance of ride comfort and load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, providing ample stopping power even when towing. An Anti-lock Braking System (ABS) was standard equipment. The truck’s heavy weight and long wheelbase contributed to its stability, especially when towing.
Market Reception & Comparison
The 6.0L V8/automatic Sierra 2500HD was generally well-received by critics and consumers alike. It was praised for its strong towing capacity, comfortable ride, and relatively affordable price compared to diesel-powered alternatives. However, its fuel economy was a common criticism, as the 6.0L V8 is not known for its efficiency. Compared to the Duramax diesel engine, the 6.0L offered less torque and lower fuel economy, but it was significantly less expensive to purchase and maintain. The 6.0L also offered a simpler and potentially more reliable powertrain compared to the more complex diesel engine.
Legacy
The Vortec L96 6.0L V8, when paired with the 6L90 automatic transmission, has proven to be a relatively reliable powertrain. While not without its potential issues (such as Active Fuel Management system problems in some years), it is generally considered a durable and long-lasting engine. Today, these trucks are readily available on the used market at reasonable prices, making them an attractive option for buyers seeking a capable and affordable heavy-duty pickup. Their continued presence on roads and job sites is a testament to their durability and practicality.
