The GMC Envoy II, specifically the 4.2i 24V (291 Hp) 4×4 Automatic variant, represents the second generation of GMC’s mid-size SUV, produced from 2006 to 2008. Built on the GMT360 platform shared with the Chevrolet TrailBlazer and Buick Rainier, the Envoy II aimed to provide a blend of truck-based durability with improved on-road refinement. This particular configuration, featuring the 4.2-liter inline-six engine paired with a four-speed automatic transmission and four-wheel drive, occupied a mid-to-upper position within the Envoy II lineup, offering a balance of power, capability, and features for buyers seeking a versatile family vehicle.
Technical Specifications
| Brand | GMC |
| Model | Envoy |
| Generation | Envoy II (GMT360) |
| Type | 4.2i 24V (291 Hp) 4×4 Automatic |
| Start of production | 2006 |
| End of production | 2008 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | SUV |
| Seats | 5 |
| Doors | 5 |
| Fuel Type | Petrol (Gasoline) |
| Weight-to-power ratio | 7.1 kg/Hp, 141.3 Hp/tonne |
| Weight-to-torque ratio | 5.5 kg/Nm, 183 Nm/tonne |
| Power | 291 Hp @ 6000 rpm |
| Power per litre | 70 Hp/l |
| Torque | 377 Nm @ 4800 rpm, 278.06 lb.-ft. @ 4800 rpm |
| Maximum engine speed | 6300 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | LL8 |
| Engine displacement | 4160 cm3, 253.86 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 | 10.2 l, 10.78 US qt | 8.97 UK qt |
| Kerb Weight | 2060 kg, 4541.52 lbs |
| Max. weight | 2608 kg, 5749.66 lbs |
| Max load | 548 kg, 1208.13 lbs |
| Trunk (boot) space – minimum | 1127 l, 39.8 cu. ft. |
| Trunk (boot) space – maximum | 2268 l, 80.09 cu. ft. |
| Fuel tank capacity | 83.3 l, 22.01 US gal | 18.32 UK gal |
| Permitted trailer load with brakes (12%) | 2812 kg, 6199.4 lbs |
| Length | 4866 mm, 191.57 in. |
| Width | 1897 mm, 74.69 in. |
| Height | 1826 mm, 71.89 in. |
| Wheelbase | 2869 mm, 112.95 in. |
| Front track | 1603 mm, 63.11 in. |
| Rear (Back) track | 1576 mm, 62.05 in. |
| Ride height (ground clearance) | 203 mm, 7.99 in. |
| Minimum turning circle (turning diameter) | 11.1 m, 36.42 ft. |
| Approach angle | 29° |
| Departure angle | 23° |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 4 gears, automatic transmission Hydra-Matic |
| Front suspension | Double wishbone |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Hydraulic Steering |
| Tires size | 245/65 R17 |
| Wheel rims size | 7.0J x 17 |
Powertrain & Engine Architecture
The heart of this Envoy II variant is the LL8 4.2-liter inline-six engine. This engine, a member of GM’s Vortec family, utilizes a cast iron block with aluminum cylinder heads. It features dual overhead camshafts (DOHC) and four valves per cylinder, contributing to its relatively high output for a naturally aspirated engine of its size. The multi-port fuel injection system delivers fuel directly to each cylinder, optimizing combustion. The engine’s 10.3:1 compression ratio strikes a balance between power and efficiency. The Hydra-Matic 4L60-E four-speed automatic transmission was the standard pairing for this engine. While not the most modern transmission by 2006 standards, it was known for its durability and smooth operation. The 4L60-E features electronic control for optimized shift points and torque converter lockup, contributing to fuel efficiency during highway cruising.
Driving Characteristics
The 291 horsepower and 278 lb-ft of torque provided by the 4.2-liter engine and four-speed automatic delivered adequate performance for everyday driving and towing. Acceleration was respectable, though not particularly brisk, with a 0-60 mph time estimated around 8.5-9.5 seconds. The automatic transmission’s gear ratios were tuned for a balance of acceleration and fuel economy. Compared to the available V8 engine in the Envoy II, this inline-six offered less raw power, but it was generally smoother and quieter in operation. Compared to manual transmission versions (which were rare), the automatic provided greater convenience, especially in city driving. However, it did result in a slight reduction in fuel economy and a less engaging driving experience.
Equipment & Trim Levels
The 4.2i 4×4 Automatic trim typically included features such as air conditioning, power windows and locks, cruise control, and an AM/FM stereo with a CD player. Higher trim levels, such as the SLE and SLT, added features like leather upholstery, heated seats, a premium sound system, and a sunroof. Optional extras included a navigation system, rear-seat entertainment system, and upgraded alloy wheels. The interior design was functional and comfortable, with a focus on practicality rather than luxury.
Chassis & Braking
The Envoy II’s chassis featured a traditional body-on-frame construction, providing robust durability and towing capacity. The front suspension utilized an independent double wishbone design, while the rear suspension employed an independent multi-link setup. This configuration aimed to provide a comfortable ride and reasonable handling. Braking duties were handled by ventilated discs at the front and solid discs at the rear. Anti-lock brakes (ABS) were standard, enhancing safety during emergency braking situations. The 4×4 system offered a variety of modes, including 2WD, 4HI, and 4LO, allowing drivers to adapt to various road conditions.
Market Reception & Comparison
The GMC Envoy II, particularly the 4.2i 4×4 Automatic, was generally well-received by critics as a capable and versatile SUV. It was praised for its comfortable ride, spacious interior, and strong towing capacity. However, some reviewers noted that the four-speed automatic transmission felt dated compared to newer transmissions with more gears. Fuel economy was also a point of criticism, as the Envoy II was not particularly fuel-efficient. Compared to the V8-powered Envoy II, the 4.2-liter version offered a more affordable price point and slightly better fuel economy, making it an attractive option for buyers who didn’t require the extra power.
Legacy
The LL8 4.2-liter inline-six engine, while not known for being exceptionally long-lived, proved to be reasonably reliable in the Envoy II. Common issues included oil leaks and occasional sensor failures. The 4L60-E transmission, when properly maintained, was also generally durable. Today, the Envoy II 4.2i 4×4 Automatic can be found on the used car market at relatively affordable prices. Its combination of space, capability, and affordability makes it a viable option for buyers seeking a budget-friendly SUV. However, potential buyers should be aware of the vehicle’s age and potential maintenance needs.
