The GMC Sierra 2500HD, in its fifth generation (GMTT1XX), received a significant facelift for the 2024 model year. This article focuses specifically on the Crew Cab Standard Bed configuration equipped with the 6.6-liter V8 gasoline engine producing 401 horsepower, paired with a 10-speed automatic transmission. Introduced in 2023 with the refreshed GMTT1XX platform, this variant represents a balance between capability and everyday usability within the Sierra 2500HD lineup, targeting buyers needing substantial towing and hauling capacity without opting for the diesel-powered models.
Technical Specifications
| Brand | GMC |
| Model | Sierra 2500HD |
| Generation | Sierra 2500HD V (GMTT1XX, facelift 2024) Crew Cab Standard Bed |
| Type (Engine) | 6.6 V8 (401 Hp) Automatic |
| Start of production | 2023 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 7.6 kg/Hp, 132.3 Hp/tonne |
| Weight-to-torque ratio | 4.8 kg/Nm, 207.5 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 |
| 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 | 3032 kg (6684.42 lbs) |
| Max. weight | 4604 kg (10150.08 lbs) |
| Max load | 1572 kg (3465.67 lbs) |
| Fuel tank capacity | 136 l (35.93 US gal | 29.92 UK gal) |
| Permitted trailer load with brakes (12%) | 7257 kg (15998.95 lbs) |
| Length | 6369 mm (250.75 in) |
| Width including mirrors | 2079 mm (81.85 in) |
| Height | 2027 mm (79.8 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) | 257 mm (10.12 in) |
| 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 | 10 gears, automatic transmission Allison |
| Front suspension | Independent torsion bar, double wishbone |
| 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 | 245/75 R17; 265/70 R17; 275/70 R18; 275/65 R20 |
| Wheel rims size | 7.5J x 17; 8J x 18; 8.5J x 20 |
INTRODUCTION
The 2024 GMC Sierra 2500HD, as part of the GMTT1XX generation, represents GMC’s heavy-duty pickup truck offering. The facelift introduced for 2024 brought updated styling, enhanced technology, and refinements to the interior. The Crew Cab Standard Bed configuration provides a spacious cabin and a versatile bed length, making it suitable for both work and family use. The 6.6-liter V8 gasoline engine with 401 horsepower and the 10-speed Allison automatic transmission positions this variant as a strong contender for buyers who prioritize gasoline power and a smooth driving experience over the higher torque offered by the Duramax diesel engine.
Powertrain & Engine Architecture
At the heart of this Sierra 2500HD is the GM L8T 6.6-liter naturally aspirated V8 engine. This engine utilizes direct fuel injection, a robust cast iron block, and aluminum cylinder heads. The overhead valve (OHV) valvetrain contributes to its durability and relatively simple maintenance. The engine produces 401 horsepower at 5200 rpm and 629 lb-ft of torque at 4000 rpm. The 10-speed Allison automatic transmission, a significant upgrade from previous generations, is designed to efficiently manage the engine’s power and provide smooth, responsive shifting. This transmission features electronically controlled shifts and a wide gear ratio spread, optimizing both towing performance and fuel economy. The transmission is known for its durability and ability to handle the high torque output of the V8 engine.
Driving Characteristics
The 6.6L V8 and 10-speed automatic combination delivers a noticeable balance of power and refinement. While not offering the sheer pulling power of the Duramax diesel, the gasoline engine provides ample torque for most heavy-duty tasks, including towing trailers, hauling payloads, and navigating challenging terrain. The 10-speed transmission keeps the engine in its optimal power band, resulting in confident acceleration and smooth highway cruising. Compared to earlier Sierra 2500HD models with older transmissions, the 2024 version offers a more refined and controlled driving experience. The gear ratios are well-spaced, allowing for quick downshifts when needed and minimizing engine noise at highway speeds. However, fuel economy remains a consideration, as gasoline engines generally consume more fuel than diesel alternatives under heavy load.
Equipment & Trim Levels
The Sierra 2500HD Crew Cab Standard Bed 6.6L V8 typically comes standard with a comprehensive suite of features. These include a user-friendly infotainment system with a touchscreen display, Apple CarPlay and Android Auto compatibility, and a rearview camera. Higher trim levels, such as the Denali, add premium features like leather upholstery, heated and ventilated seats, a premium sound system, and advanced driver-assistance systems. Standard safety features include ABS, stability control, and multiple airbags. Optional extras often include a power sunroof, a navigation system, and a trailering package with features like trailer sway control and integrated trailer brake controller.
Chassis & Braking
The Sierra 2500HD utilizes a robust body-on-frame construction, providing a solid foundation for heavy-duty applications. The front suspension features an independent torsion bar setup with double wishbones, while the rear suspension employs a traditional leaf spring design. This configuration balances ride comfort with load-carrying capacity. The braking system consists of ventilated discs on all four wheels, providing ample stopping power even when towing heavy loads. The front brakes measure 355×40 mm, while the rear brakes are 360×34 mm. An anti-lock braking system (ABS) is standard, enhancing safety and control during emergency braking situations.
Market Reception & Comparison
Critics generally praised the 2024 Sierra 2500HD for its updated styling, improved interior, and enhanced technology. The 6.6L V8 engine was recognized for its ample power and smooth operation, although it was often noted that the Duramax diesel offered superior towing capacity and fuel economy. Compared to the 6.6L Duramax diesel, the gasoline engine variant is typically less expensive to purchase but may incur higher fuel costs over the long term, especially for those who frequently tow or haul heavy loads. The gasoline engine is often favored by buyers who prioritize initial cost and a simpler maintenance schedule.
Legacy
The L8T 6.6L V8 engine, coupled with the 10-speed Allison automatic transmission, represents a significant step forward in GMC’s heavy-duty truck offerings. While the Duramax diesel remains the preferred choice for those prioritizing maximum towing capacity and fuel efficiency, the gasoline engine variant provides a compelling alternative for buyers who value a balance of power, refinement, and affordability. The GMTT1XX platform, with its updated technology and improved features, has solidified the Sierra 2500HD’s position as a competitive player in the heavy-duty truck segment. As these trucks enter the used car market, they are expected to maintain strong resale values due to their reputation for durability and capability.
