The GMC Sierra 1500 III, specifically the Extended Cab Long Box configuration with the 4.8-liter Vortec V8 engine and four-wheel drive, was a mainstay of GMC’s full-size pickup truck lineup from 2007 to 2013. Representing the third generation of the Sierra 1500 (GMT900 platform), this variant occupied a middle ground in the trim hierarchy, offering a balance between capability, space, and affordability. It catered to buyers needing a versatile truck for both work and personal use, without the premium price tag of higher-end trims like the Denali. This model year marked a significant redesign for the Sierra, focusing on improved interior refinement and enhanced mechanical components.
Technical Specifications
| Brand | GMC |
| Model | Sierra 1500 |
| Generation | Sierra 1500 III (GMT900) Extended Cab Long Box |
| Type (Engine) | 4.8 Vortec V8 (295 Hp) 4WD Automatic |
| Start of production | 2007 |
| End of production | 2013 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 6 |
| Doors | 2 |
| Fuel consumption (urban) | 16.8 l/100 km (14 US mpg, 16.8 UK mpg) |
| Fuel consumption (extra urban) | 13.1 l/100 km (18 US mpg, 21.6 UK mpg) |
| Fuel Type | Petrol (Gasoline) |
| Power | 295 Hp @ 5600 rpm |
| Torque | 414 Nm @ 4600 rpm (305.35 lb.-ft. @ 4600 rpm) |
| Maximum engine speed | 6000 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | LY2 |
| Engine displacement | 4807 cm3 (293.34 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 96.01 mm (3.78 in.) |
| Piston Stroke | 83.06 mm (3.27 in.) |
| Compression ratio | 9.1:1 |
| 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 | 12.7 l (13.42 US qt | 11.17 UK qt) |
| Max. weight | 3175 kg (6999.68 lbs.) |
| Trunk (boot) space – maximum | 2138 l (75.5 cu. ft.) |
| Fuel tank capacity | 128 l (33.81 US gal | 28.16 UK gal) |
| Length | 6325 mm (249.02 in.) |
| Width including mirrors | 2029 mm (79.88 in.) |
| Height | 1868 mm (73.54 in.) |
| Wheelbase | 4001 mm (157.52 in.) |
| Front track | 1730 mm (68.11 in.) |
| Rear (Back) track | 1702 mm (67.01 in.) |
| Ride height (ground clearance) | 240 mm (9.45 in.) |
| Minimum turning circle | 15.6 m (51.18 ft.) |
| Approach angle | 16.4° |
| Departure angle | 22° |
| Ramp-over angle | 17.8° |
| 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 4.8-liter (293 cubic inch) LY2 Vortec V8 engine. This engine is a member of the Vortec family, known for its robust construction and relatively simple design. It features a cast iron block with aluminum cylinder heads, and utilizes a 9.1:1 compression ratio. The engine employs a traditional overhead valve (OHV) valvetrain with two valves per cylinder. Fuel delivery is managed by a multi-port fuel injection system, providing adequate fuel atomization for efficient combustion. The LY2 produces 295 horsepower at 5600 rpm and 305 lb-ft of torque at 4600 rpm. The engine is longitudinally mounted in the chassis. Paired with the LY2 is the 4L80-E four-speed automatic transmission, a Hydra-Matic design known for its durability and suitability for truck applications. While not the most modern transmission in terms of gear count, it provided smooth shifts and reliable performance for the intended use case.
Driving Characteristics
The 4.8L V8 and 4L80-E automatic combination delivered adequate, but not exhilarating, performance. Acceleration was sufficient for everyday driving and towing moderate loads. The four-speed automatic, while reliable, lacked the close gear ratios of more modern transmissions, resulting in a noticeable drop in engine speed during highway cruising. This meant the engine often operated at higher RPMs to maintain speed, impacting fuel economy. Compared to the available 5.3L V8 or the diesel options, the 4.8L felt less powerful, particularly when fully loaded or climbing steep grades. However, the 4.8L’s simpler design and lower output also contributed to its generally good reliability. The 4WD system provided enhanced traction in inclement weather and off-road conditions, making it a capable all-season vehicle.
Equipment & Trim Levels
The Extended Cab Long Box 4.8L 4WD Sierra 1500 typically came standard with features like air conditioning, power windows and locks, a basic audio system, and cloth upholstery. The extended cab provided additional rear seating, though legroom was limited. Optional extras included upgraded audio systems, power-adjustable seats, a towing package, and various convenience features. Trim levels varied, but generally offered increasing levels of interior refinement and exterior styling enhancements. The interior typically featured a functional, truck-oriented design with durable materials. The dashboard layout was straightforward and easy to use, prioritizing practicality over luxury.
Chassis & Braking
The GMT900 platform utilized a body-on-frame construction, providing a robust and durable chassis. The front suspension consisted of independent coil springs, while the rear suspension employed a traditional leaf spring setup. This configuration prioritized load-carrying capacity and durability over ride comfort. Braking duties were handled by disc brakes up front and drum brakes in the rear. Anti-lock brakes (ABS) were standard. The rear drum brakes were a cost-saving measure, and while adequate for most applications, they didn’t offer the same stopping power as rear discs. The truck’s relatively high ground clearance (9.45 inches) allowed for moderate off-road capability.
Market Reception & Comparison
The 4.8L Sierra 1500 was generally well-received as a capable and affordable full-size pickup. Critics noted its comfortable ride, spacious cabin (especially with the extended cab), and strong towing capacity. However, the 4.8L engine was often criticized for its lack of power compared to the 5.3L V8. Fuel economy was also a concern, particularly given the truck’s size and weight. Compared to the 5.3L V8, the 4.8L offered a lower purchase price and potentially better long-term reliability due to its simpler design. The diesel options, while more expensive, provided superior fuel economy and torque for heavy-duty applications.
Legacy
The LY2 Vortec 4.8L engine, when properly maintained, proved to be a remarkably durable powertrain. Common issues included oil leaks and occasional misfires, but these were generally addressable with routine maintenance. Today, these trucks are readily available on the used market at relatively affordable prices. They remain popular choices for those seeking a dependable and capable pickup truck for work or recreational use. The 4L80-E transmission is also known for its longevity, making these trucks a good value for buyers looking for a reliable and long-lasting vehicle. While not the most technologically advanced truck of its era, the GMC Sierra 1500 III 4.8L 4WD remains a solid and practical choice in the used truck market.
