The Mercedes-Benz S 350 BlueEFFICIENCY, part of the long-wheelbase (V221) S-Class range following the 2009 facelift, represented a compelling blend of luxury, performance, and efficiency. Produced from 2011 to 2013, this variant occupied a key position in the S-Class lineup, offering a more accessible entry point into the flagship sedan while still delivering the renowned Mercedes-Benz experience. It was primarily marketed in Europe and Asia, where the longer wheelbase S-Class was particularly favored for its increased rear passenger space.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | S-class |
| Generation | S-class Long (V221, facelift 2009) |
| Type (Engine) | S 350 BlueEFFICIENCY (306 Hp) G-TRONIC |
| Start of production | 2011 |
| End of production | 2013 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 10.3-10.7 l/100 km (22.8 – 22 US mpg, 27.4 – 26.4 UK mpg, 9.7 – 9.3 km/l) |
| Fuel consumption (extra urban) | 6.1-6.4 l/100 km (38.6 – 36.8 US mpg, 46.3 – 44.1 UK mpg, 16.4 – 15.6 km/l) |
| Fuel consumption (combined) | 7.7-8.0 l/100 km (30.5 – 29.4 US mpg, 36.7 – 35.3 UK mpg, 13 – 12.5 km/l) |
| CO2 emissions | 179-186 g/km |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 7.1 sec |
| Acceleration 0 – 62 mph | 7.1 sec |
| Acceleration 0 – 60 mph | 6.7 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 5 |
| Weight-to-power ratio | 6.2 kg/Hp, 161.1 Hp/tonne |
| Weight-to-torque ratio | 5.1 kg/Nm, 194.7 Nm/tonne |
| Power | 306 Hp @ 6500 rpm |
| Power per litre | 87.5 Hp/l |
| Torque | 370 Nm @ 3500 rpm (272.9 lb.-ft. @ 3500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | M 276.950 |
| Engine displacement | 3498 cm3 (213.46 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | V-engine |
| Compression ratio | 12:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Direct injection |
| Engine oil capacity | 6.5 l (6.87 US qt | 5.72 UK qt) |
| Kerb Weight | 1900 kg (4188.78 lbs.) |
| Max. weight | 2555 kg (5632.81 lbs.) |
| Max load | 655 kg (1444.03 lbs.) |
| Trunk (boot) space – minimum | 560 l (19.78 cu. ft.) |
| Fuel tank capacity | 83 l (21.93 US gal | 18.26 UK gal) |
| Length | 5226 mm (205.75 in.) |
| Width | 1871 mm (73.66 in.) |
| Width including mirrors | 2120 mm (83.46 in.) |
| Height | 1479 mm (58.23 in.) |
| Wheelbase | 3165 mm (124.61 in.) |
| Front track | 1600 mm (62.99 in.) |
| Rear (Back) track | 1606 mm (63.23 in.) |
| Front overhang | 888 mm (34.96 in.) |
| Rear overhang | 1173 mm (46.18 in.) |
| Minimum turning circle | 12.2 m (40.03 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Drive wheel | Rear wheel drive |
| Number of gears | 7 |
| Gearbox type | automatic transmission G-TRONIC |
| Front brakes | Disc |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Tires size | 235/55 R17 |
| Wheel rims size | 17 |
Powertrain & Engine Architecture
The S 350 BlueEFFICIENCY was powered by the M276.950 3.5-liter naturally aspirated V6 engine. This engine was a cornerstone of Mercedes-Benz’s modular engine family, known for its smooth operation and relatively high efficiency. It featured a 60-degree V-angle, aluminum alloy block and cylinder heads, and a sophisticated direct injection system. The direct injection system, operating at pressures up to 200 bar, allowed for precise fuel metering and improved combustion efficiency. The engine also incorporated variable valve timing (VVT) on both intake and exhaust camshafts, further optimizing performance and fuel economy. Paired with the engine was the 7G-TRONIC automatic transmission, a seven-speed unit renowned for its smooth and responsive shifts. This transmission was specifically tuned to complement the V6 engine’s characteristics, providing a balance between comfort and performance.
Driving Characteristics
The S 350 BlueEFFICIENCY offered a refined and comfortable driving experience. While not as overtly powerful as the V8-equipped S 500 or the AMG variants, the 306 horsepower and 370 Nm (273 lb-ft) of torque provided ample power for effortless cruising and confident overtaking. The 7G-TRONIC transmission contributed to this smoothness, with well-spaced gear ratios that kept the engine in its optimal power band. Acceleration from 0 to 60 mph took approximately 6.7 seconds, respectable for a large luxury sedan. Compared to the manual transmission options available on some S-Class models, the automatic prioritized comfort and ease of use, making it ideal for city driving and long-distance journeys. The longer wheelbase of the ‘Long’ variant further enhanced ride comfort, absorbing bumps and imperfections in the road with aplomb.
Equipment & Trim Levels
The S 350 BlueEFFICIENCY came standard with a comprehensive array of luxury features. Interior appointments typically included leather upholstery, wood trim, and a multi-function steering wheel. Standard equipment also included automatic climate control, a premium audio system, and a host of safety features such as ABS, ESP, and multiple airbags. Optional extras included features like a panoramic sunroof, upgraded leather packages, massaging seats, a rear entertainment system, and advanced driver-assistance systems like Distronic Plus adaptive cruise control and lane-keeping assist. The ‘BlueEFFICIENCY’ designation indicated the inclusion of specific fuel-saving technologies, such as optimized aerodynamics and low-rolling-resistance tires.
Chassis & Braking
The S-Class V221 utilized a fully independent suspension system, featuring air suspension with Adaptive Damping System (ADS) as standard. This system automatically adjusted the damping characteristics based on road conditions and driving style, providing a comfortable ride while maintaining good handling. The S 350 BlueEFFICIENCY was equipped with disc brakes on all four wheels, providing ample stopping power. ABS (Anti-lock Braking System) and ESP (Electronic Stability Program) were standard safety features, enhancing braking performance and stability in challenging conditions. The suspension was tuned to prioritize comfort, but still offered a secure and planted feel during cornering.
Market Reception & Comparison
The S 350 BlueEFFICIENCY was generally well-received by automotive critics. It was praised for its comfortable ride, refined interior, and relatively good fuel economy for a vehicle of its size and class. Compared to the more powerful S 500, the S 350 offered a more affordable entry point into the S-Class range without sacrificing too much in terms of luxury or refinement. The S 350 also offered better fuel economy than the V8 models, making it a more practical choice for drivers who prioritized efficiency. However, some critics noted that the V6 engine lacked the outright performance of the V8, and that the automatic transmission could occasionally feel hesitant in certain driving situations.
Legacy
The M276 engine family, including the version used in the S 350 BlueEFFICIENCY, proved to be a reliable and durable powertrain. While some early examples experienced minor issues with oil leaks or timing chain tensioners, these were generally addressed through service bulletins and updates. Today, well-maintained S 350 BlueEFFICIENCY models represent a good value on the used car market, offering a luxurious and comfortable driving experience at a relatively affordable price. The combination of a smooth V6 engine, a refined automatic transmission, and a spacious, well-equipped interior continues to appeal to buyers seeking a high-end luxury sedan.
