The Mercedes-Benz M-Class (W164) ML 300 CDI BlueEFFICIENCY, produced from 2009 to 2010, represented a mid-cycle update to the second-generation M-Class. This variant, equipped with a 3.0-liter V6 turbodiesel engine producing 190 horsepower and paired with a 7G-TRONIC automatic transmission and 4MATIC all-wheel drive, aimed to balance fuel efficiency with respectable performance within the luxury SUV segment. It sat as a middle-ground offering in the W164 lineup, positioned above the base ML 280 CDI but below the more powerful ML 350 CDI and ML 500 models. The “BlueEFFICIENCY” designation indicated the inclusion of various fuel-saving technologies.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | M-Class |
| Generation | M-Class (W164, facelift 2008) |
| Type | ML 300 CDI BlueEFFICIENCY V6 (190 Hp) 4MATIC 7G-TRONIC |
| Start of production | 2009 |
| End of production | 2010 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | SUV |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption (urban) | 10.8-11.8 l/100 km (21.8 – 19.9 US mpg) |
| Fuel consumption (extra urban) | 6.9-7.9 l/100 km (34.1 – 29.8 US mpg) |
| Fuel consumption (combined) | 8.4-9.3 l/100 km (28 – 25.3 US mpg) |
| CO2 emissions | 222-246 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 9.8 sec |
| Acceleration 0 – 60 mph | 9.3 sec |
| Maximum speed | 205 km/h (127.38 mph) |
| Emission standard | Euro 4 |
| Weight-to-power ratio | 11.1 kg/Hp |
| Weight-to-torque ratio | 4.8 kg/Nm |
| Power | 190 Hp @ 4000 rpm |
| Torque | 440 Nm @ 1400-2800 rpm (324.53 lb.-ft.) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 642.940 |
| Engine displacement | 2987 cm3 (182.28 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | V-engine |
| Cylinder Bore | 83 mm (3.27 in.) |
| Piston Stroke | 92 mm (3.62 in.) |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 8.5 l (8.98 US qt | 7.48 UK qt) |
| Coolant capacity | 9.5 l (10.04 US qt | 8.36 UK qt) |
| Kerb Weight | 2110 kg (4651.75 lbs.) |
| Max. weight | 2830 kg (6239.08 lbs.) |
| Max load | 720 kg (1587.33 lbs.) |
| Trunk (boot) space (min) | 833 l (29.42 cu. ft.) |
| Trunk (boot) space (max) | 2050 l (72.4 cu. ft.) |
| Fuel tank capacity | 95 l (25.1 US gal | 20.9 UK gal) |
| Permitted trailer load (braked) | 3500 kg (7716.18 lbs.) |
| Permitted trailer load (unbraked) | 750 kg (1653.47 lbs.) |
| Length | 4781 mm (188.23 in.) |
| Width | 1911 mm (75.24 in.) |
| Width including mirrors | 2124 mm (83.62 in.) |
| Height | 1815 mm (71.46 in.) |
| Wheelbase | 2915 mm (114.76 in.) |
| Front track | 1627 mm (64.06 in.) |
| Rear track | 1629 mm (64.13 in.) |
| Ride height (ground clearance) | 201 mm (7.91 in.) |
| Minimum turning circle | 11.6 m (38.06 ft.) |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Gearbox | 7 gears, automatic transmission G-TRONIC |
Powertrain & Engine Architecture
The ML 300 CDI BlueEFFICIENCY utilized the OM 642.940 3.0-liter V6 diesel engine. This engine was a mainstay in many Mercedes-Benz vehicles of the era, known for its robust construction and relatively smooth operation for a diesel. It featured a common rail direct injection system, delivering fuel at extremely high pressures for improved combustion efficiency and reduced emissions. The engine also incorporated a variable geometry turbocharger (VGT) and an intercooler to enhance power output and torque across a broad RPM range. The 7G-TRONIC automatic transmission, a seven-speed unit, was designed to provide smooth and efficient gear changes. It featured a torque converter lock-up clutch to minimize slippage and improve fuel economy. The transmission was electronically controlled, adapting shift points based on driving conditions and driver input.
Driving Characteristics
The 190 hp output and 440 Nm (324 lb-ft) of torque provided adequate, though not exhilarating, performance for the ML 300 CDI. Acceleration from 0-60 mph took around 9.3 seconds, making it competitive with other diesel SUVs of the time. The 7G-TRONIC transmission helped to keep the engine in its optimal power band, providing reasonably responsive acceleration. Compared to the more powerful ML 350 CDI, the ML 300 CDI felt noticeably less potent, particularly when fully loaded or tackling steep inclines. However, the ML 300 CDI offered a more relaxed driving experience, prioritizing fuel efficiency and comfort over outright speed. The automatic transmission, while smooth, lacked the engagement and control offered by the available manual transmission options in other M-Class variants.
Equipment & Trim Levels
The ML 300 CDI BlueEFFICIENCY typically came standard with features such as automatic climate control, power-adjustable front seats, a multi-function steering wheel, and an audio system with CD player. Leather upholstery was often standard, along with wood trim accents. Optional extras included a sunroof, navigation system, premium sound system, parking sensors, and heated seats. The “BlueEFFICIENCY” package included features like optimized aerodynamics, low-rolling resistance tires, and an eco start/stop system (depending on market) to further improve fuel economy. Trim levels were relatively standardized, with options primarily focused on adding convenience and luxury features.
Chassis & Braking
The W164 M-Class featured an independent suspension system all around, with double wishbones at the front and a multi-link setup at the rear. This provided a comfortable ride quality, although the vehicle’s substantial weight could be felt in corners. Stabilizer bars were fitted front and rear to reduce body roll. The braking system consisted of ventilated discs at the front and solid discs at the rear. Anti-lock brakes (ABS) and electronic stability control (ESP) were standard safety features. The 4MATIC all-wheel-drive system provided enhanced traction in various weather conditions, distributing torque between the front and rear axles as needed.
Market Reception & Comparison
The ML 300 CDI BlueEFFICIENCY was generally well-received by automotive critics as a practical and fuel-efficient luxury SUV. It offered a good balance between performance, comfort, and economy, making it an attractive option for buyers who didn’t require the extra power of the higher-spec models. Fuel economy was a key selling point, with combined fuel consumption figures ranging from 28 to 25.3 US mpg. Compared to the ML 350 CDI, the ML 300 CDI offered lower running costs but sacrificed some performance. Reliability was generally good, although some owners reported issues with the diesel particulate filter (DPF) and the complex electronic systems.
Legacy
The OM 642 engine family, including the 3.0-liter variant used in the ML 300 CDI, has proven to be remarkably durable. Well-maintained examples can accumulate high mileage with relatively few major issues. On the used car market, the ML 300 CDI BlueEFFICIENCY represents a relatively affordable entry point into the Mercedes-Benz M-Class range. However, potential buyers should be aware of the potential for DPF issues and the cost of maintaining the vehicle’s complex systems. The W164 M-Class, and specifically the ML 300 CDI, remains a popular choice for those seeking a capable and comfortable luxury SUV with reasonable running costs.
