The GMC Sierra 3500HD, specifically the V (GMTT1XX) Crew Cab Standard Bed configuration with the 6.6-liter V8 engine producing 401 horsepower, represents GMC’s heavy-duty full-size pickup truck offering from the 2020 to 2023 model years. This variant occupied a significant position within the Sierra 3500HD lineup, catering to buyers needing substantial towing and payload capacity without opting for the highest trim levels. It served as a workhorse for both commercial and personal use, balancing capability with a more accessible price point compared to the Denali or AT4 trims. The GMTT1XX platform, shared with the Chevrolet Silverado 3500HD, was a significant redesign focused on increasing interior space, improving technology, and enhancing overall capability.
Technical Specifications
| Brand | GMC |
| Model | Sierra 3500HD |
| Generation | Sierra 3500HD V (GMTT1XX) Crew Cab Standard Bed |
| Type (Engine) | 6.6 V8 (401 Hp) 4WD Automatic |
| Start of production | 2020 year |
| End of production | 2023 year |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 7.9 kg/Hp, 127.3 Hp/tonne |
| Weight-to-torque ratio | 5 kg/Nm, 199.6 Nm/tonne |
| Power | 401 Hp @ 5200 rpm |
| Torque | 629 Nm @ 4000 rpm, 463.93 lb.-ft. @ 4000 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | L8T |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 103.25 mm / 4.06 in. |
| Piston Stroke | 98 mm / 3.86 in. |
| Compression ratio | 10.8:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Direct injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV, VVT |
| Engine oil capacity | 7.6 l / 8.03 US qt | 6.69 UK qt |
| Coolant | 14.6 l / 15.43 US qt | 12.85 UK qt |
| Kerb Weight | 3151 kg / 6946.77 lbs. |
| Max. weight | 5148 kg / 11349.4 lbs. |
| Max load | 1997 kg / 4402.63 lbs. |
| Fuel tank capacity | 136 l / 35.93 US gal | 29.92 UK gal |
| Permitted trailer load with brakes (12%) | 6577 kg / 14499.8 lbs. |
| Length | 6352 mm / 250.08 in. |
| Width including mirrors | 2079 mm / 81.85 in. |
| Height | 2054 mm / 80.87 in. |
| Wheelbase | 4037 mm / 158.94 in. |
| Front track | 1731 mm / 68.15 in. |
| Rear (Back) track | 1736 mm / 68.35 in. |
| Ride height (ground clearance) | 284 mm / 11.18 in. |
| 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, 360×34 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Power steering | Hydraulic Steering |
| Tires size | 265/70 R17; 245/75 R17; 275/70 R18 |
| Wheel rims size | 7.5J x 17; 8J x 18 |
Powertrain & Engine Architecture
At the heart of this Sierra 3500HD variant lies the 6.6-liter L8T V8 gasoline engine. This engine is a naturally aspirated, overhead valve (OHV) design featuring direct fuel injection and variable valve timing (VVT). The L8T produces 401 horsepower at 5200 rpm and 464 lb-ft of torque at 4000 rpm. The direct injection system contributes to improved fuel efficiency and power delivery. The engine’s robust internal components are designed for heavy-duty applications, ensuring longevity and reliability under demanding conditions. The engine is paired with a six-speed Hydra-Matic automatic transmission, known for its durability and smooth shifting. This transmission is specifically calibrated to handle the high torque output of the 6.6L V8 and provide adequate gear ratios for towing and hauling.
Driving Characteristics
The 401 hp and 464 lb-ft of torque provide ample power for everyday driving and demanding tasks. While not as quick as lighter-duty pickups, the Sierra 3500HD delivers strong acceleration, especially when unladen. The six-speed automatic transmission offers smooth and predictable shifts, although it may occasionally hunt for the right gear when climbing steep hills with a load. The 4WD system provides excellent traction in various conditions, making it suitable for both on-road and off-road use. The truck’s substantial weight and long wheelbase contribute to a comfortable ride, but also result in noticeable body roll during cornering. Compared to the available Duramax diesel engine, this gasoline variant offers quicker throttle response but lacks the diesel’s superior towing capacity and fuel economy.
Equipment & Trim Levels
The Sierra 3500HD Crew Cab Standard Bed 6.6 V8 4WD Automatic typically came standard with features such as air conditioning, power windows and locks, a basic infotainment system with a touchscreen display, and a rearview camera. The interior upholstery was typically cloth, with options for leather available at an additional cost. Higher trim levels added features like heated and ventilated front seats, a premium sound system, and advanced safety technologies. Common optional extras included a trailer brake controller, a bed liner, and various appearance packages. The standard bed length offered a practical balance between cargo space and maneuverability.
Chassis & Braking
The Sierra 3500HD utilizes a fully boxed frame constructed from high-strength steel, providing a solid foundation for heavy-duty applications. The front suspension features coil springs and a double wishbone design, while the rear suspension employs a traditional leaf spring setup. This configuration is optimized for load-carrying capacity and stability. The braking system consists of ventilated discs at all four corners, with larger rotors and calipers on the front axle. An Anti-lock Braking System (ABS) is standard. The truck’s steering system utilizes a hydraulic power steering system, providing responsive and precise control.
Market Reception & Comparison
Critics generally praised the Sierra 3500HD for its robust construction, powerful engine options, and comfortable ride. The 6.6L V8 gasoline engine was viewed as a capable alternative to the Duramax diesel, particularly for buyers who did not require the diesel’s maximum towing capacity. However, fuel economy was a common criticism, as the gasoline engine consumed significantly more fuel than the diesel counterpart. Compared to the Ford Super Duty and Ram 3500, the Sierra 3500HD offered a competitive combination of features, capability, and value. The gasoline engine variant was often favored by buyers who prioritized initial cost over long-term fuel savings.
Legacy
The L8T 6.6L V8 engine, when paired with the six-speed Hydra-Matic transmission, has proven to be a relatively reliable powertrain. While not immune to typical maintenance requirements, such as oil changes and spark plug replacements, it has generally demonstrated good longevity. In the used car market, these Sierra 3500HD models are often sought after by buyers looking for a capable and affordable heavy-duty pickup truck. The availability of parts and service is excellent, and the truck’s robust construction ensures that it can withstand years of hard use. However, potential buyers should be aware of the engine’s relatively high fuel consumption and the importance of regular maintenance to ensure continued reliability.
