The GMC Sierra 1500 III, in the Crew Cab Short Box configuration with the 4.8-liter Vortec V8 engine and automatic transmission, was manufactured from 2010 to 2013. This variant occupied a significant position within the GMT900 generation Sierra lineup, striking a balance between capability, comfort, and affordability. Positioned as a mid-range offering, it appealed to buyers who required a full-size pickup with ample passenger space and V8 power, without incurring the higher costs associated with premium trim levels or larger displacement engines. The inclusion of FlexFuel capability provided added versatility, allowing operation on gasoline or ethanol blends up to E85.
Technical Specifications
| Brand | GMC |
| Model | Sierra 1500 |
| Generation | Sierra 1500 III (GMT900) Crew Cab Short Box |
| Type (Engine) | 4.8 Vortec V8 (302 Hp) Automatic FlexFuel |
| Start of production | 2010 |
| End of production | 2013 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 6 |
| Doors | 4 |
| Fuel consumption (urban) | 16.8 l/100 km (14 US mpg, 16.8 UK mpg) |
| Fuel consumption (extra urban) | 12.4 l/100 km (19 US mpg, 22.8 UK mpg) |
| Fuel Type | Petrol / Ethanol – E85 |
| Power | 302 Hp @ 5600 rpm |
| Power per litre | 62.8 Hp/l |
| Torque | 414 Nm @ 4600 rpm (305.35 lb.-ft. @ 4600 rpm) |
| Maximum engine speed | 6000 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | L20 |
| 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 | 8.8:1 |
| 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) |
| Trunk (boot) space – maximum | 1506 l (53.18 cu. ft.) |
| Fuel tank capacity | 98 l (25.89 US gal | 21.56 UK gal) |
| Length | 5844 mm (230.08 in.) |
| Width including mirrors | 2031 mm (79.96 in.) |
| Height | 1875 mm (73.82 in.) |
| Wheelbase | 3645 mm (143.5 in.) |
| Front track | 1732 mm (68.19 in.) |
| Rear (Back) track | 1702 mm (67.01 in.) |
| Ride height (ground clearance) | 229 mm (9.02 in.) |
| Minimum turning circle (turning diameter) | 14.4 m (47.24 ft.) |
| Approach angle | 15.3° |
| Departure angle | 22.8° |
| Ramp-over (brakeover) angle | 19.3° |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 4 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 4.8-liter (293 cubic inch) Vortec L20 V8 engine forms the core of this Sierra 1500 variant. This engine belongs to the Vortec family, recognized for its robust construction and relatively uncomplicated design. It features a cast iron engine block and aluminum cylinder heads, employing a traditional pushrod (OHV) valvetrain. The L20 utilizes sequential multi-port fuel injection, precisely delivering fuel to each intake port to enhance both efficiency and power output. The 8.8:1 compression ratio represented a compromise, balancing performance with the ability to operate on a range of fuel grades, including E85. The standard transmission pairing for this engine was the Hydra-Matic 4L80-E four-speed automatic transmission. This transmission is well-regarded for its durability and suitability for truck applications, although it lacks the efficiency offered by more contemporary transmissions with a greater number of gears.
Driving Characteristics
The combination of the 4.8L V8’s 302 horsepower and the 4L80-E transmission’s 305 lb-ft of torque delivered adequate, though not exceptional, performance. Acceleration was reasonable for a full-size pickup truck, but it didn’t match the responsiveness of models equipped with the larger 5.3L or 6.2L V8 engines. The four-speed automatic transmission, while dependable, featured relatively broad gear ratios, which could lead to noticeable engine RPM fluctuations during highway driving. Towing capacity was respectable, but owners who frequently engaged in heavy towing often preferred the more powerful engine options. The rear-wheel-drive configuration provided a conventional truck driving experience, prioritizing hauling and work-related tasks.
Equipment & Trim Levels
The 4.8L V8/automatic combination was commonly found in the SLE and SLT trim levels. Standard features typically included air conditioning, power windows and locks, a basic audio system, and cloth upholstery. The SLT trim level added enhancements such as alloy wheels, upgraded interior trim, and potentially a premium audio system. Optional extras included a navigation system, leather upholstery, a sunroof, and various towing packages. The Crew Cab configuration offered generous passenger space, making it a popular choice for families or individuals who regularly transported multiple passengers.
Chassis & Braking
The GMT900 Sierra 1500 utilized a body-on-frame construction, providing a strong and durable platform. 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 a particularly refined ride quality. The braking system featured disc brakes at the front and drum brakes at the rear, with ABS included as standard equipment. The braking performance was sufficient for typical use, but larger brakes were often found on higher trim levels or models equipped with heavier-duty towing packages.
Market Reception & Comparison
The 4.8L Sierra 1500 was generally well-received as a capable and affordable full-size pickup. Reviewers praised its comfortable ride and spacious interior, particularly in the Crew Cab configuration. However, the 4.8L engine was often criticized for lacking the power and refinement of the larger V8 options. Fuel economy was average for a vehicle of its size and class. In comparison to the 5.3L V8, the 4.8L offered a lower initial purchase price and slightly improved fuel economy, but at the cost of performance. The 4.8L also presented a more economical alternative to the diesel-powered Silverado/Sierra 1500 models.
Legacy
The L20 4.8L Vortec V8, coupled with the 4L80-E transmission, has proven to be a relatively reliable powertrain. While not entirely without potential issues – such as oil leaks and occasional problems with the Active Fuel Management system – it is generally considered a durable and long-lasting combination. In the current used car market, these Sierra 1500s offer good value for buyers seeking a capable and affordable full-size pickup. Maintenance costs are typically reasonable, and parts availability remains good. However, prospective buyers should be aware of the limitations of the four-speed automatic transmission and the lower power output compared to larger engine options.
