2007-2010 GMC Sierra 1500 III (GMT900) Regular Cab Long Box 5.3 Vortec V8 (320 Hp) 4WD Automatic FlexFuel

Technical Specifications

Brand GMC
Model Sierra 1500
Generation Sierra 1500 III (GMT900) Regular Cab Long Box
Type (Engine) 5.3 Vortec V8 (320 Hp) 4WD Automatic FlexFuel
Start of production 2007
End of production 2010
Powertrain Architecture Internal Combustion engine
Body type Pick-up
Seats 3
Doors 2
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
Weight-to-power ratio 7.1 kg/Hp, 140.9 Hp/tonne
Weight-to-torque ratio 4.9 kg/Nm, 203 Nm/tonne
Power 320 Hp @ 5200 rpm
Power per litre 60.1 Hp/l
Torque 461 Nm @ 4200 rpm (340.02 lb.-ft. @ 4200 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 2271 kg (5006.7 lbs.)
Max. weight 3084 kg (6799.06 lbs.)
Max load 813 kg (1792.36 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 1875 mm (73.82 in.)
Wheelbase 3378 mm (132.99 in.)
Front track 1730 mm (68.11 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 17°
Departure angle 23.3°
Ramp-over (brakeover) angle 21.8°
Drivetrain Architecture The Internal combustion engine (ICE) drives the rear wheels permanently, and the front wheels are driven through an electrically or mechanically operated clutch if necessary.
Drive wheel All wheel drive (4×4)
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

The GMC Sierra 1500 III, produced from 2007 to 2010, marked a significant step forward in General Motors’ full-size pickup truck lineup. This generation, known as GMT900, aimed to deliver a blend of robust capability with enhanced refinement and contemporary features. Within the Sierra 1500 range, the Regular Cab Long Box configuration equipped with the 5.3-liter Vortec V8 engine, four-wheel drive, and an automatic transmission, proved to be a popular choice for buyers who needed a versatile work truck with a comfortable driving experience. This particular variant found favor in regions where both on-road comfort and off-road capability were highly valued, such as the American Midwest and Western states.

Powertrain & Engine Architecture

The core of this Sierra 1500 variant is the 5.3-liter (325.13 cubic inch) Vortec 5300 V8 engine, internally designated as the LMG. This engine belongs to the third generation of the Small-Block Chevrolet engine family, renowned for its durability and relatively straightforward design. It features a cast iron engine block paired with aluminum cylinder heads, and operates with a 9.9:1 compression ratio. The engine utilizes a multi-port fuel injection system, precisely delivering fuel to each cylinder for optimized combustion. The overhead valve (OHV) valvetrain, while a traditional design, offered proven reliability and cost-effectiveness. A key feature was the engine’s compatibility with E85 flex-fuel, providing drivers with an alternative fuel option. The standard transmission was the Hydra-Matic 4L80-E four-speed automatic, selected for its strength and ability to manage the engine’s torque output. This transmission incorporated electronic control for smoother gear changes and improved fuel efficiency compared to earlier designs.

Driving Characteristics

The 320 horsepower and 340 lb-ft of torque generated by the 5.3L V8 and 4L80-E automatic combination provided sufficient performance for a wide range of tasks. While not as powerful as the available 6.0L V8, the 5.3L struck a good balance between power and fuel economy. Acceleration from 0 to 60 mph typically took around 7.5 to 8.5 seconds, depending on the load and road conditions. The four-speed automatic transmission, while dependable, had relatively broad gear ratios. This often resulted in the engine running at higher RPMs during highway driving, potentially impacting fuel efficiency. Compared to the manual transmission options offered on other Sierra 1500 trims, the automatic prioritized convenience over driver control and responsiveness. The 4WD system enhanced traction in challenging conditions, making it suitable for both work and recreational activities.

Equipment & Trim Levels

The Regular Cab Long Box 5.3L 4WD Sierra 1500 generally came standard with features such as air conditioning, a basic audio system, and vinyl upholstery. Work Truck (WT) trims were more basic, emphasizing functionality. Higher trim levels, like the SLE, added features like cloth upholstery, power windows and locks, and upgraded audio systems. Optional extras included a towing package, upgraded wheels, and a navigation system. The interior design was practical and durable, prioritizing usability over luxury. The long bed offered substantial cargo space, making it ideal for transporting materials or equipment.

Chassis & Braking

The GMT900 Sierra 1500 featured a fully boxed frame for increased rigidity and durability. The front suspension utilized independent coil springs, contributing to a comfortable ride. The rear suspension employed a traditional leaf spring setup, designed to handle heavier loads. The braking system consisted of disc brakes at the front and drum brakes at the rear. An ABS (Anti-lock Braking System) was standard, improving safety during emergency braking maneuvers. The steering system was a rack-and-pinion setup with power assist, providing responsive handling.

Market Reception & Comparison

The 5.3L V8/4WD/Automatic Sierra 1500 was well-received by buyers seeking a capable and versatile pickup truck. Reviewers praised its comfortable ride, strong engine, and generous cargo space. However, some critics noted that the four-speed automatic transmission felt somewhat outdated compared to newer transmissions with more gears. Fuel economy was considered average for the segment. Compared to the 4.8L V8 Sierra 1500, the 5.3L delivered significantly more power and torque. The 6.0L V8 offered even greater performance, but came at a higher price and with reduced fuel efficiency. Diesel options, like the 1.9L TDI available in some markets, provided superior fuel economy but lacked the V8’s raw power.

Legacy

The GMT900 Sierra 1500, particularly the 5.3L V8 variants, have proven to be relatively reliable vehicles over time. The Vortec 5300 engine is known for its longevity, and the 4L80-E transmission is also generally durable. These trucks are now readily available on the used car market at affordable prices. Common maintenance concerns include oil leaks, sensor failures, and wear and tear on suspension components. Despite their age, these Sierra 1500s continue to be popular choices for those needing a dependable and capable work truck.

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