The GMC Sierra 1500 III, specifically the Regular Cab Long Box configuration with the 5.3-liter Vortec V8 engine, 4WD, and automatic transmission, was a mainstay of GMC’s full-size pickup truck lineup from 2010 to 2013. Representing the GMT900 generation, this truck was designed to appeal to buyers needing a robust work truck with the capability of a V8 powertrain and the convenience of four-wheel drive. It occupied a middle ground in the Sierra 1500 range, offering more power and towing capacity than the base 4.8L V8 models, but remaining more affordable than the 6.2L V8 options. This variant was primarily sold in the North American market, catering to customers in both rural and suburban areas who required a versatile pickup for work, hauling, and everyday use.
Technical Specifications
| Brand | GMC |
| Model | Sierra 1500 |
| Generation | Sierra 1500 III (GMT900) Regular Cab Long Box |
| Type (Engine) | 5.3 Vortec V8 (315/326 Hp) 4WD Automatic FlexFuel |
| Start of production | 2010 |
| End of production | 2013 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 3 |
| Doors | 2 |
| Fuel consumption (urban) | 15.7 l/100 km (15 US mpg, 18 UK mpg) |
| Fuel consumption (extra urban) | 11.2 l/100 km (21 US mpg, 25.2 UK mpg) |
| Fuel Type | Petrol / Ethanol – E85 |
| Weight-to-power ratio | 7.2 kg/Hp |
| Weight-to-torque ratio | 5 kg/Nm |
| Power | 315 Hp @ 5200 rpm |
| Power (Ethanol – E85) | 326 Hp @ 5300 rpm |
| Torque | 454 Nm @ 4400 rpm (334.85 lb.-ft. @ 4400 rpm) |
| Torque (Ethanol – E85) | 472 Nm @ 4400 rpm |
| Maximum engine speed | 6000 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | LMG |
| Engine displacement | 5328 cm3 (325.13 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 96.01 mm (3.78 in.) |
| Piston Stroke | 91.95 mm (3.62 in.) |
| Compression ratio | 9.9:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV |
| Engine oil capacity | 5.7 l (6.02 US qt | 5.02 UK qt) |
| Coolant capacity | 14.1 l (14.9 US qt | 12.41 UK qt) |
| Kerb Weight | 2267 kg (4997.88 lbs.) |
| Max. weight | 3084 kg (6799.06 lbs.) |
| Max load | 817 kg (1801.18 lbs.) |
| Trunk (boot) space – maximum | 2138 l (75.5 cu. ft.) |
| Fuel tank capacity | 128 l (33.81 US gal | 28.16 UK gal) |
| Permitted trailer load with brakes (12%) | 4445 kg (9799.55 lbs.) |
| Length | 5702 mm (224.49 in.) |
| Width including mirrors | 2031 mm (79.96 in.) |
| Height | 1876 mm (73.86 in.) |
| Wheelbase | 3378 mm (132.99 in.) |
| Front track | 1732 mm (68.19 in.) |
| Rear (Back) track | 1702 mm (67.01 in.) |
| Ride height (ground clearance) | 241 mm (9.49 in.) |
| Minimum turning circle (turning diameter) | 15.4 m (50.52 ft.) |
| Approach angle | 16.3° |
| Departure angle | 23.3° |
| Ramp-over (brakeover) angle | 21.8° |
| Drivetrain Architecture | All wheel drive (4×4). ICE drives rear wheels, front wheels engaged via clutch. |
| Number of gears and type of gearbox | 6 gears, automatic transmission Hydra-Matic |
| Front suspension | Independent coil spring |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Disc, 330×30 mm |
| Rear brakes | Drum, 295×60 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 245/70 R17 |
| Wheel rims size | 7.5J x 17 |
Powertrain & Engine Architecture
The heart of this Sierra 1500 variant is the 5.3L (325 cubic inch) Vortec LMG V8 engine. This engine is a member of the Vortec family, known for its robust construction and relatively simple design. The LMG features a cast iron block with aluminum cylinder heads, a 9.9:1 compression ratio, and a two-valve-per-cylinder overhead valve (OHV) valvetrain. Fuel delivery is handled by a multi-port fuel injection system. A key feature of the LMG is its Active Fuel Management (AFM), or cylinder deactivation system, which shuts down four cylinders during light-load driving conditions to improve fuel economy. The engine is mated to a six-speed Hydra-Matic automatic transmission, a common and generally reliable unit in GM trucks of this era. This transmission provides smooth shifts and adequate gear ratios for both towing and everyday driving. The FlexFuel capability allows the engine to run on gasoline or a blend of up to 85% ethanol (E85), offering some flexibility at the pump.
Driving Characteristics
The 5.3L V8 with the six-speed automatic delivers a balance of power and usability. While not as quick as the 6.2L models, the 315 horsepower and 454 lb-ft of torque provide ample power for hauling and towing. The automatic transmission is tuned for smooth operation, prioritizing comfort over aggressive shifting. The gear ratios are well-suited for highway cruising, but may require downshifts for quicker acceleration or when navigating hilly terrain. Compared to the manual transmission versions, the automatic offers greater convenience, especially in stop-and-go traffic. However, it does result in a slight reduction in fuel economy and a less direct connection to the engine. The 4WD system provides enhanced traction in slippery conditions, making it suitable for both on-road and off-road use.
Equipment & Trim Levels
The Regular Cab Long Box 5.3L 4WD Sierra 1500 typically came standard with features like air conditioning, power windows and locks, a basic audio system, and a tilt steering wheel. Higher trim levels, such as the SLE and SLT, added features like upgraded upholstery, alloy wheels, a premium audio system, and additional convenience features. Optional extras included a navigation system, a sunroof, leather seats, and a trailering package. The interior was generally functional and durable, with a focus on practicality rather than luxury. The long bed provided ample cargo space, making it ideal for hauling building materials, equipment, or recreational gear.
Chassis & Braking
The GMT900 Sierra 1500 utilizes a body-on-frame construction, providing a robust and durable platform. The front suspension features independent coil springs, while the rear suspension employs a traditional leaf spring setup. This configuration provides a comfortable ride quality, although it can be somewhat bouncy when unloaded. Braking duties are handled by disc brakes up front and drum brakes in the rear. An Anti-lock Braking System (ABS) is standard. The truck’s relatively high ground clearance allows for moderate off-road capability.
Market Reception & Comparison
The 2010-2013 GMC Sierra 1500 with the 5.3L V8 and automatic transmission was generally well-received by critics and consumers. It was praised for its strong engine, comfortable ride, and capable towing capacity. However, some reviewers noted that the interior felt dated compared to newer trucks on the market. Compared to the 4.8L V8 models, the 5.3L offered a significant performance boost, while remaining more affordable than the 6.2L. Fuel economy was average for a full-size pickup truck, and the AFM system helped to improve efficiency during highway driving. Reliability was generally good, although some owners reported issues with the AFM system and the transmission.
Legacy
The GMT900 Sierra 1500, particularly the 5.3L V8 variant, remains a popular choice in the used truck market. Its robust powertrain and durable construction make it a reliable workhorse. While older models may require some maintenance, parts are readily available and relatively affordable. The LMG engine, while not the most fuel-efficient, is known for its longevity and ability to withstand heavy use. These trucks continue to be valued by those seeking a capable and affordable full-size pickup for work or recreational purposes. The combination of V8 power, 4WD capability, and a long bed makes it a versatile and practical vehicle that continues to serve its owners well.
