The Mercedes-Benz E 350 CDI BlueEFFICIENCY, produced between 2009 and 2010, represented a significant offering within the W212 E-Class range. Positioned as a premium executive sedan, this variant combined a powerful diesel engine with a sophisticated automatic transmission, targeting buyers seeking a balance of performance, efficiency, and luxury. It occupied a middle-ground position in the W212 lineup, offering more performance than the base E 250 CDI but falling short of the more potent E 500 models. The “BlueEFFICIENCY” designation denoted Mercedes-Benz’s efforts to improve fuel economy and reduce emissions through various technological enhancements.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | E-class |
| Generation | E-class (W212) |
| Type | E 350 CDI BlueEFFICIENCY V6 (231 Hp) 7G-TRONIC |
| Start of production | 2009 |
| End of production | 2010 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 8.9-9.4 l/100 km (26.4 – 25 US mpg, 31.7 – 30.1 UK mpg, 11.2 – 10.6 km/l) |
| Fuel consumption (extra urban) | 5.5-5.8 l/100 km (42.8 – 40.6 US mpg, 51.4 – 48.7 UK mpg, 18.2 – 17.2 km/l) |
| Fuel consumption (combined) | 6.8-7.1 l/100 km (34.6 – 33.1 US mpg, 41.5 – 39.8 UK mpg, 14.7 – 14.1 km/l) |
| CO2 emissions | 179-186 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 6.8 sec |
| Acceleration 0 – 62 mph | 6.8 sec |
| Acceleration 0 – 60 mph | 6.5 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 5 |
| Weight-to-power ratio | 7.6 kg/Hp, 132 Hp/tonne |
| Weight-to-torque ratio | 3.2 kg/Nm, 308.6 Nm/tonne |
| Power | 231 Hp @ 3800 rpm |
| Torque | 540 Nm @ 1600-2400 rpm (398.28 lb.-ft. @ 1600-2400 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 642.850 |
| 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.) |
| Compression ratio | 15.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | DOHC |
| Engine oil capacity | 8 l (8.45 US qt | 7.04 UK qt) |
| Kerb Weight | 1750 kg (3858.09 lbs.) |
| Max. weight | 2350 kg (5180.86 lbs.) |
| Max load | 600 kg (1322.77 lbs.) |
| Trunk (boot) space (minimum) | 540 l (19.07 cu. ft.) |
| Fuel tank capacity | 80 l (21.13 US gal | 17.6 UK gal) |
| Max. roof load | 100 kg (220.46 lbs.) |
| Permitted trailer load (with brakes) | 2100 kg (4629.71 lbs.) |
| Permitted trailer load (without brakes) | 750 kg (1653.47 lbs.) |
| Length | 4868 mm (191.65 in.) |
| Width | 1854 mm (72.99 in.) |
| Width including mirrors | 2071 mm (81.54 in.) |
| Height | 1470 mm (57.87 in.) |
| Wheelbase | 2874 mm (113.15 in.) |
| Front track | 1600 mm (62.99 in.) |
| Rear track | 1619 mm (63.74 in.) |
| Front overhang | 841 mm (33.11 in.) |
| Rear overhang | 1153 mm (45.39 in.) |
| Drag coefficient (Cd) | 0.27 |
| Minimum turning circle | 11.25 m (36.91 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears | 7 |
| Gearbox type | Automatic transmission G-TRONIC |
| Front suspension | Independent multi-link suspension |
| Rear suspension | Independent multi-link suspension |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
INTRODUCTION
The W212 E-Class, launched in 2009, represented the ninth generation of Mercedes-Benz’s mid-size executive car. The E 350 CDI BlueEFFICIENCY, a diesel-powered variant, was a key model in the European market, where diesel engines held a significant share of the premium sedan segment. It offered a compelling blend of performance and fuel efficiency, appealing to drivers who frequently undertook long journeys. In the US market, diesel options were less common, but the E 350 CDI still found a niche among those prioritizing fuel economy and torque. The W212 platform brought a more sculpted and modern design language compared to its predecessor, along with advancements in safety and technology.
Powertrain & Engine Architecture
At the heart of the E 350 CDI BlueEFFICIENCY lay the OM 642.850 3.0-liter V6 diesel engine. This engine was a cornerstone of Mercedes-Benz’s diesel offerings, known for its robust construction and refined operation. It featured a common rail direct injection system, delivering fuel at extremely high pressure for optimized combustion. The engine employed a variable geometry turbocharger (VGT) and an intercooler to enhance power and efficiency. The DOHC valvetrain, with four valves per cylinder, further contributed to the engine’s performance. The 7G-TRONIC seven-speed automatic transmission was standard, offering smooth and efficient gear changes. This transmission was known for its adaptability, providing both comfort-oriented and sport-oriented shift programs. The transmission’s gear ratios were tuned to maximize fuel economy while still providing ample acceleration.
Driving Characteristics
The E 350 CDI BlueEFFICIENCY delivered a distinctly different driving experience compared to its gasoline-powered siblings. The substantial 540 Nm (398 lb-ft) of torque, available from a low 1600 rpm, provided effortless acceleration and strong pulling power, particularly useful for overtaking maneuvers. While not as outright quick as the E 500, the E 350 CDI offered a more relaxed and refined driving experience. The 7G-TRONIC transmission contributed to this smoothness, seamlessly shifting gears and keeping the engine within its optimal power band. Compared to a manual transmission version (not widely available), the automatic offered greater convenience, especially in urban traffic. The relatively high weight of the W212 chassis was noticeable, but the well-tuned suspension provided a comfortable and controlled ride.
Equipment & Trim Levels
The E 350 CDI BlueEFFICIENCY typically came well-equipped as standard. Interior features included leather upholstery, automatic climate control, a multi-function steering wheel, and a high-quality audio system. Safety features were comprehensive, including ABS, ESP, and a suite of airbags. Optional extras included a navigation system, a panoramic sunroof, adaptive cruise control, and premium sound systems. Trim levels varied depending on the market, but generally offered options for upgraded interior materials, exterior styling enhancements, and additional driver-assistance features. The “BlueEFFICIENCY” package itself included features like optimized aerodynamics and low-rolling-resistance tires to further improve fuel economy.
Chassis & Braking
The W212 E-Class featured a sophisticated chassis design, employing an independent multi-link suspension at both the front and rear. This setup provided a good balance of ride comfort and handling precision. The E 350 CDI, due to its weight, often featured slightly stiffer spring rates compared to the lighter E 250 CDI. Braking was handled by ventilated discs on all four wheels, providing ample stopping power. ABS (Anti-lock Braking System) and ESP (Electronic Stability Program) were standard, enhancing safety and control. Steering was via a hydraulic power steering system, offering a direct and responsive feel.
Market Reception & Comparison
The E 350 CDI BlueEFFICIENCY was generally well-received by automotive critics. It was praised for its refined engine, comfortable ride, and impressive fuel economy. Compared to the E 250 CDI, the E 350 CDI offered a significant performance upgrade, while still maintaining excellent fuel efficiency. Against the E 500, it sacrificed some outright power but provided a more economical and practical option. Reliability was generally good, although diesel particulate filter (DPF) issues could occur with infrequent long-distance driving. Fuel economy figures consistently demonstrated the E 350 CDI’s efficiency, making it a popular choice for high-mileage drivers.
Legacy
The OM 642 engine family, including the OM 642.850 found in the E 350 CDI, has proven to be remarkably durable. Well-maintained examples continue to provide reliable service today. However, potential buyers should be aware of the potential for DPF issues and the cost of maintaining the complex fuel injection system. On the used car market, the E 350 CDI BlueEFFICIENCY represents a good value proposition, offering a luxurious and refined driving experience at a relatively affordable price. Its combination of performance, efficiency, and comfort ensures its continued appeal to discerning buyers.




