The Chevrolet Trailblazer I 4.2i 24V EXT, produced from 2006 to 2009, represented Chevrolet’s entry into the mid-size SUV market, specifically aimed at buyers needing substantial towing capacity and three-row seating. Positioned as a more rugged alternative to the Chevrolet Envoy, the Trailblazer EXT – denoting its extended wheelbase – offered increased cargo space and a larger fuel tank. This variant, equipped with the 4.2-liter inline-six engine and a four-speed automatic transmission, served as a mid-range offering within the Trailblazer lineup, slotting below the more powerful V8 options but above the base four-cylinder models. It was primarily sold in North America, catering to families and those requiring a versatile vehicle for both daily driving and recreational activities.
Technical Specifications
| Brand | Chevrolet |
| Model | Trailblazer |
| Generation | Trailblazer I |
| Type (Engine) | 4.2 i 24V EXT (295 Hp) |
| Start of production | 2006 |
| End of production | 2009 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | SUV |
| Seats | 7 |
| Doors | 5 |
| Fuel consumption (urban) | 15.7 l/100 km (15 US mpg, 18 UK mpg, 6.4 km/l) |
| Fuel consumption (extra urban) | 11.8 l/100 km (19.9 US mpg, 23.9 UK mpg, 8.5 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 9.4 sec |
| Acceleration 0 – 62 mph | 9.4 sec |
| Acceleration 0 – 60 mph | 8.9 sec |
| Maximum speed | 175 km/h (108.74 mph) |
| Weight-to-power ratio | 7.5 kg/Hp, 132.9 Hp/tonne |
| Weight-to-torque ratio | 5.9 kg/Nm, 168.9 Nm/tonne |
| Power | 295 Hp @ 6000 rpm |
| Power per litre | 71 Hp/l |
| Torque | 375 Nm @ 4800 rpm (276.59 lb.-ft. @ 4800 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | LL8 |
| Engine displacement | 4157 cm3 (253.68 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 93 mm (3.66 in.) |
| Piston Stroke | 102 mm (4.02 in.) |
| Compression ratio | 10.3:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | DOHC |
| Engine oil capacity | 6.6 l (6.97 US qt | 5.81 UK qt) |
| Coolant capacity | 9.2 l (9.72 US qt | 8.09 UK qt) |
| Kerb Weight | 2220 kg (4894.26 lbs.) |
| Max. weight | 2812 kg (6199.4 lbs.) |
| Max load | 592 kg (1305.14 lbs.) |
| Trunk (boot) space – minimum | 663 l (23.41 cu. ft.) |
| Trunk (boot) space – maximum | 3030 l (107 cu. ft.) |
| Fuel tank capacity | 94 l (24.83 US gal | 20.68 UK gal) |
| Length | 5279 mm (207.83 in.) |
| Width | 1895 mm (74.61 in.) |
| Height | 1957 mm (77.05 in.) |
| Wheelbase | 3277 mm (129.02 in.) |
| Front track | 1603 mm (63.11 in.) |
| Rear (Back) track | 1577 mm (62.09 in.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears | 4 |
| Gearbox type | Automatic transmission |
Powertrain & Engine Architecture
The heart of the Trailblazer I 4.2i EXT is the LL8 4.2-liter inline-six engine. This engine, a member of Chevrolet’s 3900 family, utilizes a cast iron block with aluminum cylinder heads. It features a double overhead camshaft (DOHC) valvetrain with four valves per cylinder, contributing to its respectable power output. Fuel delivery is managed by a multi-port fuel injection system, providing precise fuel metering for optimal combustion. The engine’s 10.3:1 compression ratio strikes a balance between power and efficiency. Paired with this engine is a four-speed automatic transmission, designed for smooth shifting and reliable operation. While not the most modern transmission by today’s standards, it was well-suited to the engine’s torque characteristics and the vehicle’s intended use. The transmission’s gear ratios were optimized for towing and highway cruising, prioritizing usability over outright acceleration.
Driving Characteristics
The 4.2-liter engine, producing 295 horsepower and 375 lb-ft of torque, provided adequate power for the Trailblazer EXT, but it wasn’t a particularly sporty performer. Acceleration from 0-60 mph took around 8.9 seconds, which was competitive for the segment at the time, but noticeably slower than V8-powered rivals. The four-speed automatic transmission, while smooth, lacked the responsiveness of more modern transmissions with additional gears. The gear ratios were spaced to prioritize towing capacity and fuel economy at highway speeds. In real-world driving, the Trailblazer EXT felt most comfortable cruising on the open road, where the engine’s torque allowed for effortless passing maneuvers. Compared to the higher-output V8 versions, the 4.2-liter felt less eager to rev and offered a more relaxed driving experience. Manual transmission options were not available with this engine.
Equipment & Trim Levels
The Trailblazer EXT 4.2i typically came standard with features such as air conditioning, power windows and locks, a CD player, and cloth upholstery. The extended wheelbase provided ample space for passengers and cargo. Optional extras included leather upholstery, a premium sound system, a sunroof, and rear-seat entertainment. The EXT trim also featured a larger fuel tank compared to the standard wheelbase Trailblazer, enhancing its range. The interior design was functional and durable, prioritizing practicality over luxury. The dashboard layout was straightforward, with easy-to-use controls.
Chassis & Braking
The Trailblazer EXT utilized a body-on-frame construction, providing a robust and durable platform. The front suspension featured an independent double wishbone design, while the rear suspension employed a coil spring setup. This configuration offered a comfortable ride, although it wasn’t particularly sporty. Braking duties were handled by ventilated discs on all four wheels, providing adequate stopping power. Anti-lock brakes (ABS) were standard, enhancing safety. The EXT’s longer wheelbase contributed to improved stability, especially when towing. The steering system was a hydraulic rack-and-pinion setup, offering responsive steering feel.
Market Reception & Comparison
The Trailblazer EXT 4.2i was generally well-received by critics as a capable and versatile SUV. However, its fuel economy was a common criticism, averaging around 15 mpg in the city and 19.9 mpg on the highway. Compared to the V8-powered Trailblazers, the 4.2-liter offered a more affordable price point and slightly better fuel economy, but at the expense of performance. The 4.2-liter engine was considered more reliable than some of the V8 options, requiring less frequent maintenance. It competed with other mid-size SUVs such as the Ford Explorer, Jeep Grand Cherokee, and Nissan Pathfinder.
Legacy
The Chevrolet Trailblazer I 4.2i EXT, while not a groundbreaking vehicle, remains a popular choice in the used car market due to its affordability, spacious interior, and towing capacity. The LL8 4.2-liter engine is known for its durability and relatively simple maintenance requirements. However, potential buyers should be aware of potential issues such as oil leaks and cooling system problems. Overall, the Trailblazer EXT 4.2i represents a solid and dependable SUV that continues to provide value to budget-conscious buyers seeking a versatile vehicle for family transportation and recreational activities.
