The GMC Sierra 1500 AT4 6.2L V8, introduced as part of the GMTT1XX generation’s facelift in 2022, represents a significant offering in the full-size pickup truck segment. Positioned as a premium off-road focused trim, the AT4 combines robust capability with a refined interior and a powerful powertrain. This particular configuration – Crew Cab, Short Box, paired with the 6.2-liter V8 engine and a 10-speed automatic transmission, and four-wheel drive – aims to deliver a balance of work-ready performance and comfortable daily driving. The 2022 refresh brought updated styling, enhanced technology, and continued improvements to the Sierra’s already strong foundation.
Technical Specifications
| Brand | GMC |
| Model | Sierra 1500 |
| Generation | Sierra 1500 V (GMTT1XX, facelift 2022) Crew Cab Short Box |
| Type (Engine) | AT4 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 | 6 kg/Hp, 167.5 Hp/tonne |
| Weight-to-torque ratio | 4 kg/Nm, 248.4 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 | 2508 kg (5529.19 lbs.) |
| Max. weight | 3175 kg (6999.68 lbs.) |
| Max load | 667 kg (1470.48 lbs.) |
| Fuel tank capacity | 91 l (24.04 US gal | 20.02 UK gal) |
| Permitted trailer load with brakes (12%) | 4082 kg (8999.27 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 |
| Assisting systems | ABS (Anti-lock braking system) |
| 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
At the heart of the Sierra 1500 AT4 is the 6.2-liter L87 V8 engine. This naturally aspirated powerplant utilizes direct fuel injection, a variable valve timing system, and a robust cast iron block with aluminum cylinder heads. The engine produces 420 horsepower at 5600 rpm and 460 lb-ft of torque at 4100 rpm. A key feature of the L87 is its Active Fuel Management (cylinder deactivation) system, which shuts down four cylinders during light-load driving conditions to improve fuel economy. This engine is paired with a smooth-shifting 10-speed automatic transmission (10L80) that provides a wide gear ratio spread for both towing and efficient cruising. The transmission is electronically controlled and features driver-selectable modes, including Tow/Haul.
Driving Characteristics
The combination of the 6.2L V8 and the 10-speed automatic delivers strong acceleration and impressive towing capacity. While not as fuel-efficient as smaller engine options, the V8 provides a satisfying level of power for everyday driving and demanding tasks. The 10-speed transmission keeps the engine in its optimal power band, resulting in responsive performance. Compared to the 5.3L V8 or the available Duramax diesel engine, the 6.2L offers a more immediate and powerful feel, albeit with higher fuel consumption. The AT4 trim’s off-road tuned suspension provides a comfortable ride on paved roads while also enhancing capability on rough terrain.
Equipment & Trim Levels
The AT4 trim level is well-equipped, offering a blend of luxury and functionality. Standard features include a leather-appointed interior, heated and ventilated front seats, a premium audio system, and a suite of advanced safety technologies such as automatic emergency braking, lane keep assist, and adaptive cruise control. The infotainment system features a large touchscreen display with Apple CarPlay and Android Auto compatibility. Optional extras include a power-adjustable steering column, a head-up display, and a rear-seat entertainment system. The AT4 also features unique exterior styling cues, including a distinctive grille, black chrome accents, and off-road tires.
Chassis & Braking
The Sierra 1500 AT4 utilizes a fully boxed frame for enhanced rigidity and durability. The front suspension features independent coil springs, while the rear suspension employs a traditional leaf spring setup. The AT4 trim benefits from Rancho shocks tuned for off-road performance. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power. The anti-lock braking system (ABS) is standard, along with electronic stability control and traction control.
Market Reception & Comparison
The GMC Sierra 1500 AT4 has been well-received by critics and consumers alike. It’s praised for its powerful engine, comfortable ride, and capable off-road performance. Compared to the Chevrolet Silverado, which shares the same platform, the Sierra offers a more upscale interior and distinctive styling. Fuel economy is a common criticism, as the 6.2L V8 is less efficient than the smaller engine options. However, the AT4’s overall package of features and capabilities makes it a compelling choice in the full-size pickup truck segment.
Legacy
The L87 6.2L V8 engine has proven to be a reliable and durable powerplant. While long-term reliability data is still emerging for the 2022 facelift models, the engine’s core architecture has been used in various GM vehicles for several years with a generally positive track record. On the used car market, the Sierra 1500 AT4 6.2L V8 holds its value well due to its desirable combination of power, capability, and features. Regular maintenance, including oil changes and fluid checks, is crucial for ensuring the longevity of this powertrain.
