2020-2023 GMC Sierra 3500HD V (GMTT1XX) Crew Cab Long Bed 6.6 V8 (401 Hp) SRW Automatic

Technical Specifications

The 2020-2023 GMC Sierra 3500HD Crew Cab Long Bed, powered by the 6.6-liter L8T V8 engine and paired with a six-speed Hydra-Matic automatic transmission, is a heavy-duty pickup truck designed for demanding tasks. This generation (GMTT1XX) represented a significant overhaul for the Sierra HD line, focusing on increased capability, improved interior refinement, and advanced technology. The Crew Cab configuration offered spacious seating for five passengers, while the Long Bed provided ample cargo space. This particular variant aimed to bridge the gap between work-focused trims and more luxurious options, offering a strong combination of power, comfort, and practicality.

Powertrain & Engine Architecture

At the heart of this Sierra 3500HD lies the 6.6-liter L8T V8 engine. This is a naturally aspirated, gasoline-powered engine featuring direct injection and a robust cast iron block. The engine utilizes an overhead valve (OHV) valvetrain with variable valve timing (VVT) to optimize performance and efficiency. The direct injection system delivers fuel directly into the combustion chamber, improving combustion efficiency and power output. The Hydra-Matic 6L90 six-speed automatic transmission is a heavy-duty unit designed to handle the engine’s substantial torque. This transmission features electronically controlled shifts and a tow/haul mode to optimize performance when towing heavy loads. The transmission’s gear ratios are tuned for a balance of acceleration and fuel economy, with a relatively deep first gear for launching heavy loads and higher gears for efficient highway cruising.

Driving Characteristics

The 401 horsepower and 464 lb-ft of torque delivered by the 6.6L V8 and six-speed automatic provide ample power for towing and hauling. While not as quick as lighter-duty pickups, the Sierra 3500HD offers strong acceleration, especially when unloaded. The automatic transmission shifts smoothly and predictably, and the tow/haul mode effectively manages gear selection when towing. Compared to a manual transmission equipped Sierra 3500HD, the automatic offers greater convenience, particularly in stop-and-go traffic. However, some drivers may prefer the more direct control offered by a manual. Compared to the available Duramax diesel engine, this gasoline V8 provides a different driving experience. The diesel offers significantly more torque at lower RPMs, making it ideal for extremely heavy towing, while the gasoline engine provides a more responsive feel and a higher redline.

Equipment & Trim Levels

The Sierra 3500HD offered a range of trim levels, with this 6.6L V8/automatic combination typically found in SLE, Elevation, and AT4 trims. Standard equipment generally included features like a touchscreen infotainment system with Apple CarPlay and Android Auto compatibility, a rearview camera, and keyless entry. Higher trims added features such as leather upholstery, heated and ventilated front seats, a premium sound system, and advanced safety technologies like blind-spot monitoring and rear cross-traffic alert. Optional extras included a power sunroof, a navigation system, and a bed liner. The interior design focused on functionality and durability, with comfortable seating and intuitive controls.

Chassis & Braking

The Sierra 3500HD features a fully boxed frame designed for strength and rigidity. The front suspension utilizes coil springs and a double wishbone design, while the rear suspension employs a traditional leaf spring setup. This configuration provides a comfortable ride while maintaining excellent load-carrying capacity. Braking duties are handled by ventilated disc brakes at all four corners, providing ample stopping power even when towing heavy loads. The anti-lock braking system (ABS) helps to maintain control during emergency braking situations. The rear axle ratio varied depending on the specific configuration, influencing both towing capacity and fuel economy.

Market Reception & Comparison

Critics generally praised the 2020-2023 GMC Sierra 3500HD for its powerful engine, comfortable ride, and spacious interior. The 6.6L V8/automatic combination was considered a good all-around performer, offering a balance of power and convenience. However, some reviewers noted that the gasoline engine’s fuel economy was lower than that of the Duramax diesel. Compared to competitors like the Ford Super Duty and Ram 3500, the Sierra 3500HD offered a competitive combination of features and capabilities. The Sierra’s interior was often praised for its upscale design and user-friendly technology.

Legacy

The 6.6L L8T V8 engine and Hydra-Matic 6L90 transmission have proven to be relatively reliable powertrains. While not immune to typical maintenance requirements, these components are generally known for their durability. On the used car market, Sierra 3500HD models equipped with this powertrain hold their value reasonably well, particularly those in good condition with well-documented maintenance histories. The GMTT1XX generation Sierra 3500HD represents a significant step forward in heavy-duty truck design, offering a compelling combination of capability, comfort, and technology that continues to appeal to buyers today.