The GMC Sierra 1500 AT4X, introduced with the GMTT1XX platform facelift in 2022, represents GMC’s premium off-road focused trim level for its full-size pickup truck. This particular configuration features a 6.2-liter V8 engine paired with a 10-speed automatic transmission and a four-wheel drive system. Positioned as a step up from the standard AT4, the AT4X aims to deliver enhanced capability and luxury for buyers seeking a robust and well-equipped truck. It competes directly with offerings like the Ford Raptor and Ram Power Wagon, targeting enthusiasts who demand both on-road comfort and serious off-road performance.
Technical Specifications
| Brand | GMC |
| Model | Sierra 1500 |
| Generation | Sierra 1500 V (GMTT1XX, facelift 2022) Crew Cab Short Box |
| Type (Engine) | AT4X 6.2 V8 (420 Hp) 4WD Automatic |
| Start of production | 2022 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 16.8 l/100 km (14 US mpg, 16.8 UK mpg) |
| Fuel consumption (extra urban) | 13.8 l/100 km (17 US mpg, 20.5 UK mpg) |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 5.4 kg/Hp, 186 Hp/tonne |
| Weight-to-torque ratio | 3.6 kg/Nm, 275.9 Nm/tonne |
| Power | 420 Hp @ 5600 rpm |
| Power per litre | 68.2 Hp/l |
| Torque | 623 Nm @ 4100 rpm (459.5 lb.-ft. @ 4100 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | L87 |
| Engine displacement | 6162 cm3 (376.03 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 103.25 mm (4.06 in.) |
| Piston Stroke | 92 mm (3.62 in.) |
| Compression ratio | 11.5:1 |
| 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 capacity | 12.6 l (13.31 US qt | 11.09 UK qt) |
| Kerb Weight | 2258 kg (4978.04 lbs.) |
| Max. weight | 3221 kg (7101.09 lbs.) |
| Max load | 963 kg (2123.05 lbs.) |
| Fuel tank capacity | 91 l (24.04 US gal | 20.02 UK gal) |
| Permitted trailer load with brakes (12%) | 4037 kg (8900.06 lbs.) |
| Length | 5916 mm (232.91 in.) |
| Width | 2063 mm (81.22 in.) |
| Width including mirrors | 2478 mm (97.56 in.) |
| Height | 1990 mm (78.35 in.) |
| Wheelbase | 3747 mm (147.52 in.) |
| Ride height (ground clearance) | 276 mm (10.87 in.) |
| Approach angle | 25.5° |
| Departure angle | 23.0° |
| Ramp-over (brakeover) angle | 22.7° |
| Drivetrain Architecture | All wheel drive (4×4). ICE drives rear wheels, front wheels engaged via clutch. |
| Number of gears and type of gearbox | 10 gears, automatic transmission |
| Front suspension | Independent coil spring |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Ventilated discs, 330×30 mm |
| Rear brakes | Ventilated discs, 345×20 mm |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 265/65 R18 |
| Wheel rims size | 8.5J x 18 |
Powertrain & Engine Architecture
The heart of the Sierra 1500 AT4X is the 6.2-liter L87 V8 engine. This naturally aspirated engine utilizes direct fuel injection and active fuel management (cylinder deactivation) to balance performance and efficiency. The OHV valvetrain, while traditional, contributes to the engine’s robust low-end torque. The 10-speed automatic transmission (likely a General Motors 10L80) is a key component, offering a wide gear ratio spread for both towing and off-road crawling. This transmission is known for its smooth shifts and ability to keep the engine in its optimal power band. The four-wheel drive system features an electronically controlled two-speed transfer case, allowing the driver to select between 2WD, 4HI, and 4LO modes for varying terrain conditions.
Driving Characteristics
The 6.2L V8 and 10-speed automatic combination delivers strong acceleration and ample torque for everyday driving and demanding tasks. While not as quick as some turbocharged competitors, the Sierra AT4X provides a linear power delivery that is predictable and easy to modulate. The 10-speed transmission allows for tight gear spacing, minimizing hunting and maximizing efficiency. In off-road situations, the low-range gearing and electronic locking differentials (standard on the AT4X) provide exceptional control and traction. Compared to the 5.3L V8 or the available Duramax diesel, the 6.2L offers a more spirited driving experience, but at the cost of fuel economy. The automatic transmission, while capable, may not offer the same level of driver engagement as a manual transmission (which is not available on this trim).
Equipment & Trim Levels
The AT4X trim comes standard with a comprehensive list of features, including a premium interior with leather upholstery, heated and ventilated front seats, a large touchscreen infotainment system with Apple CarPlay and Android Auto compatibility, and a suite of advanced safety technologies. Standard exterior features include unique styling cues, such as a black chrome grille and skid plates, off-road tires, and a factory lift. Optional extras include a power-adjustable steering column, a head-up display, and a premium audio system. The AT4X is positioned as the most luxurious and capable trim level in the Sierra 1500 lineup, offering a blend of comfort, convenience, and off-road prowess.
Chassis & Braking
The Sierra 1500 AT4X utilizes a fully boxed frame and independent front suspension with coil springs. The rear suspension features a solid axle with leaf springs, optimized for both load-carrying capacity and off-road articulation. The AT4X benefits from upgraded Rancho shocks, designed to provide enhanced damping and control over rough terrain. Braking duties are handled by ventilated disc brakes at all four corners, providing ample stopping power. The electronic stability control system includes off-road modes to optimize braking performance on loose surfaces.
Market Reception & Comparison
The GMC Sierra 1500 AT4X has been well-received by automotive critics and consumers alike. It is praised for its comfortable ride, powerful engine, and impressive off-road capabilities. Compared to the standard AT4, the AT4X offers a more refined interior and more advanced off-road features. Fuel economy is a common criticism, as the 6.2L V8 is not particularly efficient. However, the AT4X’s overall value proposition and strong performance have made it a popular choice among truck buyers.
Legacy
The L87 6.2L V8 engine has proven to be a reliable and durable powerplant in other GM vehicles. While long-term reliability data for the Sierra 1500 AT4X is still emerging, the engine’s proven track record suggests it should provide years of dependable service. The 10-speed automatic transmission has also demonstrated good reliability. As a used vehicle, the 2022 and later Sierra 1500 AT4X models are expected to hold their value well, due to their desirable features and strong reputation. The AT4X represents a significant step forward for GMC in the full-size truck segment, establishing it as a serious contender in the off-road performance category.
