The GMC Sierra 1500 V (GMTT1XX) Crew Cab Short Box, equipped with the 2.7-liter turbocharged engine producing 310 horsepower, was a configuration offered for the 2020 and 2021 model years. This variant occupied a key position in the Sierra 1500 lineup, serving as a more accessible entry point to the full-size truck segment while still providing a capable and modern driving experience. It represented GMC’s attempt to broaden the appeal of the Sierra, offering a balance between performance, fuel efficiency, and price. The GMTT1XX designation refers to the truck’s platform, a significant update to the previous generation, incorporating improved materials and technologies.
Technical Specifications
| Brand | GMC |
| Model | Sierra 1500 |
| Generation | Sierra 1500 V (GMTT1XX) Crew Cab Short Box |
| Type (Engine) | 2.7 Turbo (310 Hp) Automatic |
| Start of production | 2020 |
| End of production | 2021 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 11.8 l/100 km (19.9 US mpg) |
| Fuel consumption (extra urban) | 10.2 l/100 km (23.1 US mpg) |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 6.9 kg/Hp, 145.4 Hp/tonne |
| Weight-to-torque ratio | 4.5 kg/Nm, 221.9 Nm/tonne |
| Power | 310 Hp @ 5600 rpm |
| Power per litre | 113.7 Hp/l |
| Torque | 473 Nm @ 1500-4000 rpm (348.87 lb.-ft. @ 1500-4000 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | L3B |
| Engine displacement | 2727 cm3 (166.41 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Cylinder Bore | 92.25 mm (3.63 in.) |
| Piston Stroke | 102 mm (4.02 in.) |
| Compression ratio | 10:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | DOHC, VVT DI |
| Engine oil capacity | 5.7 l (6.02 US qt | 5.02 UK qt) |
| Coolant capacity | 11.8 l (12.47 US qt | 10.38 UK qt) |
| Kerb Weight | 2132 kg (4700.26 lbs.) |
| Max. weight | 3130 kg (6900.47 lbs.) |
| Max load | 998 kg (2200.21 lbs.) |
| Fuel tank capacity | 91 l (24.04 US gal | 20.02 UK gal) |
| Permitted trailer load with brakes (12%) | 3493 kg (7700.75 lbs.) |
| Length | 5886 mm (231.73 in.) |
| Width including mirrors | 2063 mm (81.22 in.) |
| Height | 1917 mm (75.47 in.) |
| Wheelbase | 3745 mm (147.44 in.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 8 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 |
| Tires size | 255/70 R17; 265/70 R17; 265/65 R18 |
| Wheel rims size | 8.0J x 17; 8.5J x 18 |
Powertrain & Engine Architecture
The heart of this Sierra 1500 variant is the GM L3B 2.7-liter turbocharged inline-four engine. This engine utilizes direct injection and a twin-scroll turbocharger to deliver a surprisingly robust 310 horsepower and 473 lb-ft of torque. The engine also incorporates Active Fuel Management (cylinder deactivation) and Auto Stop/Start technologies to improve fuel economy. The L3B engine is a significant departure from traditional American V6 and V8 offerings, representing a move towards smaller, more efficient engines. The engine is longitudinally mounted, driving the rear wheels through an eight-speed automatic transmission (8L45). This transmission is known for its smooth shifting and wide gear ratios, contributing to both fuel efficiency and responsive acceleration.
Driving Characteristics
The 2.7-liter turbo engine, paired with the eight-speed automatic, provides a different driving experience compared to the larger V8 engines available in the Sierra 1500 lineup. While it doesn’t offer the same raw power or towing capacity as the 5.3L or 6.2L V8s, it delivers ample torque for everyday driving and moderate towing needs. The turbocharger provides a noticeable boost in power, particularly at lower RPMs, making it feel more powerful than its displacement might suggest. The eight-speed transmission keeps the engine in its optimal power band, resulting in smooth acceleration. Compared to manual transmission options (not available with this engine), the automatic prioritizes convenience and ease of use. The gear ratios are tuned for a balance between fuel economy and performance, with a relatively tall final drive ratio.
Equipment & Trim Levels
The 2.7-liter turbo engine was typically offered on the SLE, Elevation, and AT4 trim levels of the Sierra 1500. Standard features generally included a 7-inch touchscreen infotainment system with Apple CarPlay and Android Auto compatibility, keyless entry, and a rearview camera. Higher trim levels added features such as leather upholstery, heated and ventilated seats, a larger touchscreen display, and advanced safety technologies like automatic emergency braking and lane departure warning. Optional extras included a premium audio system, a power sunroof, and various appearance packages.
Chassis & Braking
The Sierra 1500 V (GMTT1XX) utilizes a fully boxed frame, contributing to its robust construction and towing capability. The front suspension features independent coil springs, while the rear suspension employs a traditional leaf spring setup. This configuration provides a comfortable ride quality while maintaining a respectable payload capacity. Braking duties are handled by ventilated disc brakes on all four wheels, with the front discs measuring 330x30mm and the rear discs measuring 345x20mm. Anti-lock brakes (ABS) are standard. The braking system is adequate for the truck’s weight and performance, but it doesn’t offer the same stopping power as some of the higher-performance trims.
Market Reception & Comparison
The 2.7-liter turbo Sierra 1500 received mixed reviews. Critics praised its fuel efficiency and surprisingly strong torque output, but some found it lacking the refinement and power of the V8 engines. Compared to the 5.3L V8, the 2.7T offered better fuel economy but less overall performance. The 2.7T was positioned as a more affordable and fuel-conscious alternative to the V8s, appealing to buyers who didn’t require heavy-duty towing or hauling capabilities. Reliability reports have been generally positive, with the L3B engine proving to be a relatively durable powerplant.
Legacy
The 2.7-liter turbocharged engine has become a mainstay in the GMC Sierra 1500 lineup, demonstrating GM’s commitment to offering more fuel-efficient options in the full-size truck segment. While the initial GMTT1XX models (2020-2021) have a relatively short production run, they represent an important step in the evolution of the Sierra 1500. On the used car market, these models offer a compelling value proposition, providing a capable and well-equipped truck at a lower price point than the V8-powered variants. The L3B engine’s long-term reliability appears to be solid, making it a viable option for buyers seeking a dependable and fuel-efficient full-size truck.
