The GMC Envoy II XL (GMT370) 4.2i 24V, equipped with a 291 horsepower engine and four-wheel drive, was a mid-size SUV produced by General Motors for the 2006 model year. Representing a refresh of the GMT370 platform, the Envoy II aimed to offer a blend of space, capability, and comfort within the competitive SUV segment. This particular variant, featuring the 4.2-liter inline-six engine paired with a four-speed automatic transmission, occupied a position in the middle of the Envoy lineup, offering a step up in performance from the base V6 models while remaining more accessible than the potential for a future V8 offering. Production was limited to a single model year, making it a relatively uncommon vehicle today.
Technical Specifications
| Brand | GMC |
| Model | Envoy |
| Generation | Envoy II XL (GMT370) |
| Type (Engine) | 4.2i 24V (291 Hp) 4×4 Automatic |
| Start of production | 2006 |
| End of production | 2006 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | SUV |
| Seats | 7 |
| Doors | 5 |
| Fuel Type | Petrol (Gasoline) |
| Maximum speed | 175 km/h (108.74 mph) |
| Weight-to-power ratio | 7.7 kg/Hp, 129.1 Hp/tonne |
| Weight-to-torque ratio | 6 kg/Nm, 167.3 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 | 13.1 l (13.84 US qt | 11.53 UK qt) |
| Kerb Weight | 2254 kg (4969.22 lbs.) |
| Max. weight | 2903 kg (6400.02 lbs.) |
| Max load | 649 kg (1430.8 lbs.) |
| Trunk (boot) space – minimum | 594 l (20.98 cu. ft.) |
| Trunk (boot) space – maximum | 3041 l (107.39 cu. ft.) |
| Fuel tank capacity | 96.1 l (25.39 US gal | 21.14 UK gal) |
| Permitted trailer load with brakes (12%) | 2630 kg (5798.16 lbs.) |
| Length | 5271 mm (207.52 in.) |
| Width | 1897 mm (74.69 in.) |
| Height | 1917 mm (75.47 in.) |
| Wheelbase | 3275 mm (128.94 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) | 12.6 m (41.34 ft.) |
| Approach angle | 34° |
| Departure angle | 23.3° |
| 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 the Envoy II XL 4.2i was the LL8 engine, a 4.2-liter (253.86 cubic inches) inline-six cylinder powerplant. This engine was a member of GM’s Atlas family of inline-six engines, known for its relatively smooth operation and decent power output. The LL8 featured a cast iron block with aluminum cylinder heads, dual overhead camshafts (DOHC), and four valves per cylinder. Fuel delivery was handled by a multi-port fuel injection system, providing precise fuel metering for optimal combustion. The engine produced 291 horsepower at 6000 rpm and 278 lb-ft of torque at 4800 rpm. This power was channeled through a four-speed Hydra-Matic automatic transmission to all four wheels via a standard all-wheel-drive system.
Driving Characteristics
The 4.2-liter engine and four-speed automatic combination provided adequate, though not exhilarating, performance. Acceleration was reasonable for its size and weight, but it lacked the punch of some competitors with V8 engines. The automatic transmission was tuned for smooth shifts and everyday drivability, prioritizing comfort over sporty responsiveness. The four-speed configuration, while sufficient, was beginning to feel dated compared to newer transmissions with more gears. The all-wheel-drive system provided enhanced traction in inclement weather and on slippery surfaces, making it a capable vehicle for a variety of conditions. The gear ratios were optimized for highway cruising, but could feel somewhat strained when towing or climbing steep hills.
Equipment & Trim Levels
The Envoy II XL 4.2i typically came standard with features such as air conditioning, power windows and locks, a CD player, and cloth upholstery. The “XL” designation indicated a step up in trim level, often including features like alloy wheels, upgraded interior trim, and a premium sound system. Optional extras included leather upholstery, a sunroof, a navigation system, and a rear entertainment system. Safety features included anti-lock brakes (ABS) and a suite of airbags.
Chassis & Braking
The Envoy II XL utilized a body-on-frame construction, providing a robust and durable platform. The front suspension consisted of an independent double wishbone setup, while the rear suspension employed an independent multi-link design. This configuration aimed to balance ride comfort with handling stability. Braking duties were handled by ventilated discs at the front and solid discs at the rear. The ABS system helped to prevent wheel lockup during hard braking, enhancing safety and control. The steering system was a hydraulic rack-and-pinion setup, providing responsive and precise steering feel.
Market Reception & Comparison
The 2006 GMC Envoy II XL 4.2i received mixed reviews. Critics praised its spacious interior, comfortable ride, and standard all-wheel drive. However, some criticized its dated four-speed automatic transmission and relatively modest fuel economy compared to newer SUVs. Compared to the base V6 Envoy models, the 4.2i offered a significant performance boost, but at a higher price point. It positioned itself as a middle-ground option, appealing to buyers who wanted more power than the base engine but didn’t necessarily need the expense or fuel consumption of a potential V8.
Legacy
The GMC Envoy II XL 4.2i, being a single-year model, has become something of a niche vehicle in the used car market. The LL8 engine, while generally reliable, is known to be susceptible to oil consumption issues as it ages. Regular maintenance, including oil changes and coolant flushes, is crucial for ensuring its longevity. The four-speed automatic transmission, while durable, is not as efficient as more modern transmissions. Despite these potential issues, the Envoy II XL 4.2i remains a capable and comfortable SUV, offering a good value for buyers seeking a spacious, all-wheel-drive vehicle at an affordable price. Its relatively limited production run has also contributed to a growing interest among collectors and enthusiasts.
