The GMC Sierra 3500HD IV (GMTK2XX) Double Cab Long Box, equipped with the 6.0-liter V8 engine producing 360 horsepower and paired with a four-wheel-drive system and automatic transmission, was a mainstay of GMC’s heavy-duty truck lineup from 2015 to 2019. This configuration represented a balance between capability and everyday usability within the Sierra 3500HD range, targeting buyers needing substantial towing and hauling capacity without necessarily opting for the diesel-powered models. It occupied a middle ground, offering more power and capability than the base engine options, but at a lower price point than the more specialized diesel trims.
Technical Specifications
| Brand | GMC |
| Model | Sierra 3500HD |
| Generation | Sierra 3500HD IV (GMTK2XX) Double Cab Long Box |
| Type (Engine) | 6.0 V8 (360 Hp) 4WD SRW 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 | 8.4 kg/Hp, 118.8 Hp/tonne |
| Weight-to-torque ratio | 5.9 kg/Nm, 169.9 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 | 16.1 l, 17.01 US qt | 14.17 UK qt |
| Kerb Weight | 3031 kg, 6682.21 lbs. |
| Max. weight | 4990 kg, 11001.07 lbs. |
| Max load | 1959 kg, 4318.86 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%) | 6305 kg, 13900.15 lbs. |
| Length | 6321 mm, 248.86 in. |
| Width including mirrors | 2045 mm, 80.51 in. |
| Height | 1980 mm, 77.95 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) | 223 mm, 8.78 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, 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 |
| Wheel rims size | 7.5J x 17; 8J x 18 |
Powertrain & Engine Architecture
At the heart of this Sierra 3500HD variant lies the Vortec L96 6.0-liter V8 engine. 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 employs a traditional overhead valve (OHV) valvetrain with variable valve timing (VVT) to optimize performance and fuel efficiency. Fuel delivery is managed by a multi-port fuel injection system, providing precise fuel metering. The engine produces 360 horsepower at 5400 rpm and 515 lb-ft of torque at 4200 rpm.
The engine is mated to a six-speed Hydra-Matic automatic transmission. This transmission was designed to handle the high torque output of the V8 engine and provide smooth, reliable shifting. The automatic transmission, combined with the four-wheel-drive system, allows for confident towing and hauling in various conditions. The 4WD system typically features an electronically controlled transfer case, allowing the driver to switch between two-wheel drive and four-wheel drive modes as needed.
Driving Characteristics
The 6.0-liter V8 and six-speed automatic combination in the Sierra 3500HD delivers a noticeable step up in performance compared to the base engine options. While not as quick as some lighter-duty trucks, the Sierra 3500HD provides ample power for towing heavy loads and navigating challenging terrain. The automatic transmission offers smooth shifts, but can sometimes feel hesitant when downshifting for passing maneuvers. The gear ratios are optimized for towing, prioritizing low-end torque over outright acceleration. Compared to the diesel variants, this gasoline engine is quieter and offers a more familiar driving experience for those accustomed to traditional V8 engines. However, it lacks the diesel’s superior torque and fuel economy when heavily loaded.
Equipment & Trim Levels
The Double Cab Long Box configuration offered a spacious interior with seating for five passengers. Standard features typically included air conditioning, power windows and locks, a basic audio system, and vinyl upholstery. Higher trim levels, such as the LT and SLT, added features like leather upholstery, heated seats, a premium audio system, and advanced safety technologies. Optional extras included a navigation system, a rear-seat entertainment system, and various towing packages. The Double Cab configuration provided a useful blend of passenger space and cargo bed length, making it suitable for both work and family use.
Chassis & Braking
The Sierra 3500HD features a heavy-duty chassis designed to withstand the stresses of frequent towing and hauling. The front suspension utilizes coil springs and a double wishbone design, while the rear suspension employs a traditional leaf spring setup. This combination provides a comfortable ride while maintaining excellent load-carrying capacity. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power. An anti-lock braking system (ABS) is standard, enhancing safety during emergency braking situations. The rear axle typically featured a single rear wheel (SRW) configuration, although dual rear wheel (DRW) options were available for even greater towing capacity.
Market Reception & Comparison
The 6.0-liter V8-powered Sierra 3500HD received generally positive reviews for its capability and value. Critics praised its strong towing capacity and comfortable ride. However, some noted that its fuel economy was lower than that of the diesel-powered models, especially when towing heavy loads. Compared to the 6.6-liter Duramax diesel engine, the 6.0-liter V8 offered a lower initial cost but sacrificed fuel efficiency and ultimate towing capacity. The V8 was often seen as a good choice for buyers who didn’t require the maximum towing capacity of the diesel but still needed a capable heavy-duty truck.
Legacy
The GMTK2XX generation Sierra 3500HD, particularly the 6.0-liter V8 variant, has proven to be a reliable and durable truck. The Vortec L96 engine is known for its longevity, and the Hydra-Matic transmission is generally considered to be robust. On the used car market, these trucks remain popular among buyers seeking a capable and affordable heavy-duty pickup. While maintenance costs can be higher than some newer trucks, the relatively simple design of the L96 engine makes it relatively easy to repair. The Sierra 3500HD IV continues to be a workhorse for many owners, demonstrating its enduring value and capability.
