The Hummer H3 3.7i 20V, produced from 2006 to 2009, represented General Motors’ attempt to capture a segment of the off-road SUV market with a more manageable size and price point than the larger H1 and H2 models. Positioned as the entry-level offering in the H3 lineup, the 3.7i 20V (245 hp) 4×4 variant aimed to provide capable four-wheel drive performance with a relatively accessible price tag. It was a key model for attracting a broader customer base to the Hummer brand, appealing to those seeking a rugged aesthetic and off-road capability without the extreme size and fuel consumption of its predecessors. The H3 was built on a modified version of the GM GMT350 platform, shared with the Chevrolet Colorado and GMC Canyon mid-size pickups.
Technical Specifications
| Brand | Hummer |
| Model | H3 |
| Generation | H3 |
| Type (Engine) | 3.7i 20V (245 Hp) 4×4 |
| Start of production | 2006 |
| End of production | 2009 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Off-road vehicle, SUV |
| Seats | 5 |
| 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 consumption (combined) | 13.8 l/100 km (17 US mpg, 20.5 UK mpg, 7.2 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Maximum speed | 158 km/h (98.18 mph) |
| Weight-to-power ratio | 8.7 kg/Hp, 114.9 Hp/tonne |
| Weight-to-torque ratio | 6.5 kg/Nm, 153.8 Nm/tonne |
| Power | 245 Hp @ 5600 rpm |
| Power per litre | 67.1 Hp/l |
| Torque | 328 Nm @ 4600 rpm (241.92 lb.-ft. @ 4600 rpm) |
| Maximum engine speed | 6300 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | LLR |
| Engine displacement | 3653 cm3 (222.92 cu. in.) |
| Number of cylinders | 5 |
| Engine configuration | Inline |
| Cylinder Bore | 95.5 mm (3.76 in.) |
| Piston Stroke | 102 mm (4.02 in.) |
| Compression ratio | 10:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | DOHC, CVVT |
| Engine oil capacity | 5.7 l (6.02 US qt | 5.02 UK qt) |
| Coolant | 9.5 l (10.04 US qt | 8.36 UK qt) |
| Kerb Weight | 2132 kg (4700.26 lbs.) |
| Max. weight | 2654 kg (5851.07 lbs.) |
| Max load | 522 kg (1150.81 lbs.) |
| Trunk (boot) space – minimum | 835 l (29.49 cu. ft.) |
| Trunk (boot) space – maximum | 1575 l (55.62 cu. ft.) |
| Fuel tank capacity | 87 l (22.98 US gal | 19.14 UK gal) |
| Length | 4742 mm (186.69 in.) |
| Width | 1897 mm (74.69 in.) |
| Height | 1872 mm (73.7 in.) |
| Wheelbase | 2842 mm (111.89 in.) |
| Front track | 1651 mm (65 in.) |
| Rear (Back) track | 1664 mm (65.51 in.) |
| Ride height (ground clearance) | 216 mm (8.5 in.) |
| Drag coefficient (Cd) | 0.55 |
| Minimum turning circle (turning diameter) | 11.3 m (37.07 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 5 gears, manual transmission |
| Front suspension | Torsion |
| Rear suspension | Leaf spring |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Tires size | 265/75 R16 |
| Wheel rims size | 16 |
Powertrain & Engine Architecture
The H3 3.7i 20V was powered by the LLR inline-five cylinder engine, a 3.7-liter (3653 cc) naturally aspirated powerplant. This engine was a relatively new design for GM, featuring a cast iron block and aluminum cylinder heads. It utilized a multi-port fuel injection system and a double overhead camshaft (DOHC) valvetrain with variable valve timing (CVVT) on both intake and exhaust valves. This CVVT system aimed to improve both performance and fuel efficiency. The engine produced 245 horsepower at 5600 rpm and 328 Nm (241.92 lb-ft) of torque at 4600 rpm. The engine’s longitudinal mounting and the standard five-speed manual transmission contributed to its rear-wheel-biased all-wheel-drive system. While an automatic transmission was available, the manual was often preferred by enthusiasts for its more direct feel and improved control in off-road situations.
Driving Characteristics
The 3.7i 20V with the five-speed manual transmission offered a reasonably engaging driving experience, especially considering the H3’s size and weight. Acceleration was adequate, but not particularly brisk, with a 0-60 mph time estimated around 8.5 seconds. The engine’s torque curve provided decent low-end grunt for off-road crawling, but it did require downshifting for quicker passing maneuvers on the highway. The manual transmission’s gear ratios were well-suited for both on-road cruising and off-road rock crawling. Compared to the more powerful H3 Alpha with its 5.3-liter V8, the 3.7i felt noticeably less potent, but it also offered better fuel economy and a lighter front end, which some drivers preferred for off-road handling. The automatic transmission, while offering convenience, diminished the driving experience, resulting in slower acceleration and less engine braking.
Equipment & Trim Levels
The H3 3.7i 20V typically came standard with features such as air conditioning, power windows and locks, a CD player, and basic cloth upholstery. The interior design was functional and rugged, reflecting the vehicle’s off-road focus. Optional extras included a premium sound system, leather upholstery, sunroof, and upgraded off-road packages with features like a locking rear differential and skid plates. The H3 offered a relatively limited range of trim levels, with the 3.7i serving as the base model. Higher trims added cosmetic enhancements and additional convenience features, but the core mechanical components remained largely the same.
Chassis & Braking
The H3’s chassis featured a body-on-frame construction, providing a robust foundation for off-road use. The front suspension utilized torsion bars, while the rear suspension employed leaf springs. This setup prioritized durability and load-carrying capacity over refined on-road handling. The braking system consisted of ventilated discs at the front and solid discs at the rear, equipped with an anti-lock braking system (ABS). The H3’s relatively high curb weight of 2132 kg (4700.26 lbs) contributed to its somewhat ponderous handling characteristics on paved roads.
Market Reception & Comparison
The Hummer H3 3.7i 20V received mixed reviews from automotive critics. While its off-road capability and rugged styling were generally praised, its fuel economy and on-road handling were often criticized. Compared to other SUVs in its class, such as the Jeep Wrangler and Toyota 4Runner, the H3 offered a unique blend of style and capability, but it often fell short in terms of refinement and fuel efficiency. The 3.7i variant was seen as a more practical and affordable option than the H3 Alpha, appealing to buyers who prioritized value and fuel economy over outright performance. However, its relatively low horsepower and torque output limited its appeal to those seeking a truly high-performance off-road vehicle.
Legacy
The Hummer H3, and specifically the 3.7i 20V variant, has developed a modest following in the used car market. The LLR inline-five engine is generally considered to be reliable, although regular maintenance is crucial. Common issues include oil leaks and sensor failures. The H3’s body-on-frame construction and robust drivetrain make it a capable off-road vehicle, and its unique styling continues to attract attention. However, its poor fuel economy and relatively high maintenance costs can be deterrents for some buyers. Today, the H3 3.7i 20V represents a relatively affordable entry point into the world of Hummer ownership, offering a taste of the brand’s rugged heritage and off-road capability.
