2023 GMC Sierra 2500HD V (GMTT1XX facelift ) Crew Cab Long Bed 6.6 Duramax TD V8 (470 Hp) 4WD Automatic

The GMC Sierra 2500HD V (GMTT1XX, facelift 2024) Crew Cab Long Bed, equipped with the 6.6-liter Duramax Turbo Diesel V8 engine producing 470 horsepower and paired with a 10-speed automatic transmission and four-wheel drive, represents GMC’s heavy-duty pickup truck offering for the 2024 model year. Introduced as part of the GMTT1XX generation’s mid-cycle refresh, this variant builds upon the established reputation of the Sierra 2500HD for capability and refinement. Production began in 2023, and this configuration is positioned as a premium offering within the 2500HD lineup, targeting buyers who require substantial towing and hauling capacity alongside a comfortable and well-equipped cabin.

Technical Specifications

INTRODUCTION

The 2024 GMC Sierra 2500HD Crew Cab Long Bed with the 6.6L Duramax diesel and 10-speed automatic represents a significant evolution of GMC’s heavy-duty truck line. Part of the GMTT1XX platform, which received a substantial facelift for the 2024 model year, this variant is designed to appeal to customers needing serious towing and hauling capabilities without sacrificing comfort or modern technology. The Crew Cab configuration provides ample passenger space, while the Long Bed offers increased cargo versatility. This particular trim level sits near the top of the 2500HD range, offering a balance of luxury features and work-ready functionality.

Powertrain & Engine Architecture

At the heart of this Sierra 2500HD is the GM Duramax L5P 6.6-liter turbocharged diesel V8 engine. This engine is a cornerstone of GM’s heavy-duty truck strategy, known for its robust construction and impressive torque output. The L5P utilizes a cast iron block, aluminum cylinder heads, and a forged steel crankshaft. It employs a diesel commonrail fuel injection system, delivering fuel at extremely high pressures for efficient combustion. The engine features an overhead valve (OHV) valvetrain, a design choice favored for its durability and low-end torque characteristics. A variable geometry turbocharger and intercooler further enhance performance. The 10-speed Allison automatic transmission is specifically calibrated to handle the engine’s substantial torque, providing smooth and efficient power delivery. This transmission features electronically controlled shifts and a wide gear ratio spread, optimizing performance for both towing and everyday driving.

Driving Characteristics

The combination of the 470 horsepower and 1322 lb-ft of torque delivered by the Duramax engine and the 10-speed Allison transmission results in a driving experience that prioritizes effortless power. Acceleration, even with a substantial load, is strong and confident. The 10-speed transmission keeps the engine within its optimal power band, minimizing the need for frequent downshifts. Compared to gasoline-powered 2500HD models, the diesel offers significantly more low-end torque, making it ideal for towing heavy trailers or navigating challenging terrain. While not as quick-revving as a gasoline engine, the Duramax provides a smooth and linear power delivery. Compared to earlier 2500HD models with older transmissions, the 10-speed Allison offers improved fuel economy and a more refined driving experience.

Equipment & Trim Levels

The 2500HD Crew Cab Long Bed with the Duramax engine is typically offered in higher trim levels such as Denali or AT4. Standard features generally include a premium infotainment system with a large touchscreen display, Apple CarPlay and Android Auto compatibility, leather upholstery, heated and ventilated front seats, and a premium sound system. Available options include a power-adjustable steering column, a rear-seat entertainment system, a head-up display, and advanced safety features such as adaptive cruise control and lane departure warning. The Denali trim, in particular, adds unique exterior styling cues, such as a distinctive grille and chrome accents, along with exclusive interior appointments.

Chassis & Braking

The Sierra 2500HD features a fully boxed frame designed for strength and rigidity. The front suspension utilizes an independent torsion bar setup with double wishbone components, providing a comfortable ride and precise handling. The rear suspension employs a traditional leaf spring design, optimized for heavy-duty hauling. Braking duties are handled by ventilated disc brakes at all four corners, providing ample stopping power even when towing. An Anti-lock Braking System (ABS) is standard. The heavy-duty chassis and braking system are designed to handle the truck’s substantial weight and towing capacity.

Market Reception & Comparison

The GMC Sierra 2500HD with the Duramax diesel engine consistently receives positive reviews for its towing capability, comfortable ride, and refined interior. Critics often praise the engine’s power and efficiency, as well as the smooth operation of the 10-speed Allison transmission. Compared to competitors such as the Ford Super Duty and Ram 2500, the Sierra 2500HD is often seen as offering a more luxurious and refined driving experience. Fuel economy, while improved with the 10-speed transmission, remains a consideration for owners, as diesel fuel prices can fluctuate. Reliability has generally been good, although diesel engines can be more complex and potentially more expensive to repair than gasoline engines.

Legacy

The Duramax diesel engine has become a benchmark in the heavy-duty truck segment, known for its longevity and durability. The L5P version, found in the 2024 Sierra 2500HD, continues this tradition. These trucks, when properly maintained, are expected to provide many years of reliable service. On the used market, Sierra 2500HD models equipped with the Duramax engine command a premium price due to their reputation for capability and longevity. The combination of the powerful engine, smooth transmission, and comfortable cabin makes this variant a desirable choice for buyers seeking a heavy-duty truck that can handle both work and personal use.