The GMC Sierra 2500HD IV (GMTK2XX) Crew 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. It was positioned as a workhorse for those needing substantial towing and payload capacity, but also desiring the space and amenities of a crew cab configuration. This generation Sierra 2500HD was a direct competitor to Ford’s Super Duty and Ram’s 2500 series trucks, all vying for dominance in the increasingly popular heavy-duty truck segment.
Technical Specifications
| Brand | GMC |
| Model | Sierra 2500HD |
| Generation | Sierra 2500HD IV (GMTK2XX) Crew Cab Long Box |
| Type (Engine) | 6.0 V8 (360 Hp) Automatic |
| Start of production | 2015 year |
| End of production | 2019 year |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 8 kg/Hp, 125.3 Hp/tonne |
| Weight-to-torque ratio | 5.6 kg/Nm, 179.3 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 |
| 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 | 9.7:1 |
| 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 | 2873 kg, 6333.88 lbs |
| Max. weight | 4309 kg, 9499.72 lbs |
| Max load | 1436 kg, 3165.84 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%) | 6486 kg, 14299.18 lbs |
| Length | 6563 mm, 258.39 in |
| Width including mirrors | 2045 mm, 80.51 in |
| Height | 1981 mm, 77.99 in |
| Wheelbase | 4258 mm, 167.64 in |
| Front track | 1748 mm, 68.82 in |
| Rear (Back) track | 1709 mm, 67.28 in |
| Ride height (ground clearance) | 211 mm, 8.31 in |
| Minimum turning circle (turning diameter) | 17.1 m, 56.1 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 | 245/75 R17; 265/70 R17; 265/70 R18; 265/60 R20 |
| Wheel rims size | 7.5J x 17; 8J x 18; 8.5J x 20 |
INTRODUCTION
The GMC Sierra 2500HD IV, specifically the Crew Cab Long Box configuration with the 6.0-liter V8 and automatic transmission, debuted in 2015 as part of the GMTK2XX platform generation. This generation represented a significant overhaul for GMC’s heavy-duty trucks, focusing on increased capability, refined interiors, and improved technology. The 6.0L V8/automatic pairing was a popular choice, offering a balance between power and usability for owners who frequently towed or hauled heavy loads, but didn’t necessarily require the diesel engine’s higher price tag and more complex maintenance. It served as a work truck for many, but also appealed to those wanting a comfortable and capable daily driver.
Powertrain & Engine Architecture
At the heart of this Sierra 2500HD variant lies the Vortec L96 6.0-liter V8 engine. This engine is a member of GM’s Vortec family, known for its robust construction and reliable performance. The L96 features a cast iron block and aluminum cylinder heads, utilizing a 9.7:1 compression ratio and a two-valve-per-cylinder (OHV) configuration with variable valve timing (VVT). Fuel delivery is managed by a multi-port fuel injection system. The engine produces 360 horsepower at 5400 rpm and 515 lb-ft of torque at 4200 rpm. This torque output is crucial for heavy-duty applications. The engine is longitudinally mounted in the chassis.
The engine is paired with a six-speed Hydra-Matic automatic transmission. This transmission was designed to handle the substantial torque output of the 6.0L V8 and provide smooth, reliable shifting. The transmission’s gear ratios are optimized for both towing and everyday driving, with a relatively deep first gear for launching heavy loads and higher gears for efficient highway cruising. The Hydra-Matic transmission was known for its durability, but some owners reported occasional issues with the torque converter or electronic control module.
Driving Characteristics
The 6.0L V8 and automatic transmission combination delivers a capable, if not exhilarating, driving experience. Acceleration is adequate for a heavy-duty truck, but the focus is clearly on low-end torque for towing and hauling. The automatic transmission shifts smoothly under normal driving conditions, but can sometimes feel hesitant when downshifting for passing maneuvers. Compared to the available Duramax diesel engine, the 6.0L V8 offers significantly less torque, resulting in a lower maximum towing capacity. However, the gasoline engine is quieter and less expensive to maintain. Compared to a manual transmission equipped 6.0L, the automatic provides ease of use, especially in stop-and-go traffic or when navigating challenging terrain while towing.
Equipment & Trim Levels
The Sierra 2500HD IV Crew Cab Long Box 6.0L Automatic was available in various trim levels, including SLE and SLT. The SLE trim typically included standard features such as air conditioning, power windows and locks, a basic audio system, and cloth upholstery. The SLT trim added features like leather upholstery, heated front seats, a premium audio system, and additional chrome exterior trim. Optional extras included a navigation system, a rear-seat entertainment system, and various towing packages. The Crew Cab configuration provided ample space for passengers, making it a comfortable option for families or work crews.
Chassis & Braking
The Sierra 2500HD features a robust chassis designed to withstand the stresses of heavy-duty use. The front suspension utilizes a coil spring and double wishbone setup with a transverse stabilizer bar, while the rear suspension employs a traditional leaf spring configuration. This setup provides a comfortable ride, even when the truck is heavily loaded. Braking duties are handled by ventilated disc brakes on all four wheels, with ABS (Anti-lock Braking System) as standard equipment. The front brakes measure 350x40mm, while the rear brakes are 360x34mm. The braking system is adequate for most applications, but owners who frequently tow heavy loads may want to consider upgrading to a more robust braking system.
Market Reception & Comparison
The GMC Sierra 2500HD IV with the 6.0L V8 and automatic transmission was generally well-received by critics and consumers. It was praised for its comfortable ride, spacious interior, and capable performance. However, some critics noted that the 6.0L V8 lacked the towing capacity and fuel efficiency of the Duramax diesel engine. Compared to the diesel variant, the 6.0L offered a lower initial cost and simpler maintenance requirements. Fuel economy was typical for a heavy-duty truck, averaging around 14-16 mpg in combined driving. Reliability was generally good, but some owners reported issues with the transmission and electrical system.
Legacy
The GMC Sierra 2500HD IV (GMTK2XX) Crew Cab Long Box 6.0 V8 Automatic remains a popular choice in the used truck market today. Its robust powertrain and capable chassis make it a reliable workhorse for those needing a heavy-duty truck. While the diesel variants command a higher price, the 6.0L V8 offers a more affordable and accessible option. The engine’s simplicity makes it relatively easy and inexpensive to repair, contributing to its long-term appeal. These trucks are often found with high mileage, but well-maintained examples can provide many more years of service.
