The Mercedes-Benz M-Class (W164) ML 550 V8 4MATIC, produced from 2007 to 2008, represented the high-performance variant of the second-generation M-Class SUV. Positioned as the flagship model within the W164 range, it offered a significant step up in power and luxury compared to the ML 350 and ML 320 models. This vehicle was primarily aimed at the North American market, where larger displacement engines and powerful SUVs were highly sought after, though it was also available in other regions. The ML 550 combined Mercedes-Benz’s renowned build quality with a robust V8 engine and a sophisticated all-wheel-drive system, offering a compelling package for buyers seeking both performance and practicality.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | M-Class |
| Generation | M-Class (W164) |
| Type | ML 550 V8 (388 Hp) 4MATIC 7G-TRONIC |
| Start of production | 2007 |
| End of production | 2008 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | SUV |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption (urban) | 17.6-17.9 l/100 km (13.4 – 13.1 US mpg, 16.1 – 15.8 UK mpg, 5.7 – 5.6 km/l) |
| Fuel consumption (extra urban) | 10-10.3 l/100 km (23.5 – 22.8 US mpg, 28.2 – 27.4 UK mpg, 10 – 9.7 km/l) |
| Fuel consumption (combined) | 12.8-13.1 l/100 km (18.4 – 18 US mpg, 22.1 – 21.6 UK mpg, 7.8 – 7.6 km/l) |
| CO2 emissions | 304-311 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.8 sec |
| Acceleration 0 – 62 mph | 5.8 sec |
| Acceleration 0 – 60 mph | 5.5 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 4 |
| Weight-to-power ratio | 5.6 kg/Hp, 177.6 Hp/tonne |
| Weight-to-torque ratio | 4.1 kg/Nm, 242.6 Nm/tonne |
| Power | 388 Hp @ 6000 rpm |
| Power per litre | 78.1 Hp/l |
| Torque | 530 Nm @ 2800 rpm (390.91 lb.-ft. @ 2800 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M 273.963 |
| Engine displacement | 4966 cm3 (303.04 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 97 mm (3.82 in.) |
| Piston Stroke | 84 mm (3.31 in.) |
| Compression ratio | 10:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Engine oil capacity | 9 l (9.51 US qt | 7.92 UK qt) |
| Coolant | 12 l (12.68 US qt | 10.56 UK qt) |
| Kerb Weight | 2185 kg (4817.1 lbs.) |
| Max. weight | 2830 kg (6239.08 lbs.) |
| Max load | 645 kg (1421.98 lbs.) |
| Trunk (boot) space – minimum | 551 l (19.46 cu. ft.) |
| Trunk (boot) space – maximum | 2050 l (72.4 cu. ft.) |
| Fuel tank capacity | 95 l (25.1 US gal | 20.9 UK gal) |
| Length | 4788 mm (188.5 in.) |
| Width | 1911 mm (75.24 in.) |
| Height | 1840 mm (72.44 in.) |
| Wheelbase | 2915 mm (114.76 in.) |
| Front track | 1627 mm (64.06 in.) |
| Rear (Back) track | 1629 mm (64.13 in.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears and type of gearbox | 7 gears, automatic transmission |
| Front suspension | Double wishbone |
| Rear suspension | Spring Strut |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Tires size | 255/55 R19 |
Powertrain & Engine Architecture
The heart of the ML 550 is the M273.963 5.0-liter naturally aspirated V8 engine. This engine, a cornerstone of Mercedes-Benz’s powertrain lineup during the mid-2000s, features a three-valve-per-cylinder design (two intake, one exhaust) and a relatively high 10:1 compression ratio. It utilizes a multi-port fuel injection system, delivering fuel directly into the intake ports. The engine produces 388 horsepower at 6000 rpm and 530 Nm (390.91 lb-ft) of torque at 2800 rpm. The engine is longitudinally mounted in the front of the vehicle. Paired with the engine is the 7G-TRONIC seven-speed automatic transmission, known for its smooth shifting and efficiency. This transmission offered a wide range of gear ratios, optimizing both acceleration and fuel economy. The 4MATIC all-wheel-drive system distributes power between the front and rear axles, enhancing traction and stability in various driving conditions.
Driving Characteristics
The ML 550’s 5.5-second 0-60 mph acceleration time was impressive for a full-size SUV of its era. The V8 engine delivered strong, linear power throughout the rev range, providing effortless acceleration for highway merging and overtaking. The 7G-TRONIC transmission contributed to a refined driving experience, with smooth and almost imperceptible gear changes. Compared to the ML 350, which offered a V6 engine, the ML 550 provided a significantly more powerful and responsive driving experience. While the ML 550 didn’t offer the fuel efficiency of the diesel-powered ML 320 CDI, it provided a more traditional and refined driving experience favored by many American buyers. The all-wheel-drive system provided confident handling in inclement weather and on varied terrain.
Equipment & Trim Levels
The ML 550 came standard with a generous array of features, reflecting its position as the premium model in the M-Class lineup. Standard equipment included leather upholstery, power-adjustable front seats with memory function, dual-zone automatic climate control, a premium sound system, and a sunroof. Optional extras included a navigation system, rear-seat entertainment system, and upgraded interior trim options. The exterior typically featured chrome accents and larger alloy wheels to distinguish it from the lower trim levels. The interior dashboard configuration was consistent across the W164 range, but the ML 550 often featured unique wood or metallic trim options.
Chassis & Braking
The W164 M-Class utilized a robust chassis with a double wishbone front suspension and a spring strut rear suspension. This setup provided a comfortable ride while maintaining good handling characteristics. The ML 550 featured ventilated disc brakes on all four wheels, providing ample stopping power. An Anti-lock Braking System (ABS) was standard, enhancing safety and control during emergency braking situations. Due to the increased weight of the V8 engine, the ML 550 often featured slightly stiffer suspension components compared to the V6 models to maintain optimal handling balance.
Market Reception & Comparison
The ML 550 was generally well-received by automotive critics, who praised its powerful engine, refined transmission, and luxurious interior. However, its fuel economy was often cited as a drawback, particularly compared to the diesel-powered alternatives. Compared to competitors like the BMW X5 and Porsche Cayenne, the ML 550 offered a compelling combination of performance, luxury, and value. The ML 550’s reliability was generally considered good, although some owners reported issues with the air suspension system, a common concern across the W164 range.
Legacy
The M-Class (W164) ML 550 V8 4MATIC remains a desirable SUV in the used car market, particularly for buyers seeking a powerful and luxurious vehicle. The M273 engine, while known for its complexity, is generally considered reliable when properly maintained. Regular maintenance, including oil changes and coolant flushes, is crucial to ensure the longevity of the engine and transmission. The 7G-TRONIC transmission is also known for its durability, but may require occasional servicing. Today, the ML 550 represents a blend of classic Mercedes-Benz engineering and modern SUV practicality, offering a unique driving experience for enthusiasts.
