The Mercedes-Benz C 300d, part of the W205 C-Class facelift introduced in 2018, represented a significant offering in the premium compact executive car segment. Produced through 2021, this variant combined a potent 2.0-liter turbocharged diesel engine with the sophisticated 9G-TRONIC nine-speed automatic transmission, and rear-wheel drive. Positioned as a mid-to-upper trim level within the C-Class range, the C 300d aimed to deliver a balance of performance, efficiency, and refinement, appealing to buyers seeking a more dynamic driving experience than the base C 220d, but without the outright performance focus of the C 43 AMG. It was primarily marketed in Europe and other regions where diesel engines remained popular, offering a compelling alternative to gasoline-powered rivals like the BMW 3 Series and Audi A4.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | C-class |
| Generation | C-class (W205, facelift 2018) |
| Type (Engine) | C 300d (245 Hp) 9G-TRONIC |
| Start of production | 2018 |
| End of production | 2021 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption at Low speed (WLTP) | 5.4 l/100 km (43.6 US mpg, 52.3 UK mpg, 18.5 km/l) |
| Fuel consumption at very high speed (WLTP) | 6.3 l/100 km (37.3 US mpg, 44.8 UK mpg, 15.9 km/l) |
| CO2 emissions (WLTP) | 142-166 g/km |
| Fuel consumption (economy) – urban | 6.0-6.3 l/100 km (39.2 – 37.3 US mpg, 47.1 – 44.8 UK mpg, 16.7 – 15.9 km/l) |
| Fuel consumption (economy) – extra urban | 4.3-4.8 l/100 km (54.7 – 49 US mpg, 65.7 – 58.9 UK mpg, 23.3 – 20.8 km/l) |
| Fuel consumption (economy) – combined | 4.9-5.4 l/100 km (48 – 43.6 US mpg, 57.6 – 52.3 UK mpg, 20.4 – 18.5 km/l) |
| CO2 emissions | 130-142 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 5.9 sec |
| Acceleration 0 – 62 mph | 5.9 sec |
| Acceleration 0 – 60 mph | 5.6 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6 |
| Weight-to-power ratio | 6.4 kg/Hp, 157.1 Hp/tonne |
| Weight-to-torque ratio | 3.1 kg/Nm, 320.5 Nm/tonne |
| Power | 245 Hp |
| Power per litre | 125.6 Hp/l |
| Torque | 500 Nm @ 1600-2400 rpm (368.78 lb.-ft. @ 1600-2400 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | OM 654.920 |
| Engine displacement | 1950 cm3 (119 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Engine oil capacity | 6.8 l (7.19 US qt | 5.98 UK qt) |
| Coolant | 10 l (10.57 US qt | 8.8 UK qt) |
| Kerb Weight | 1560 kg (3439.21 lbs.) |
| Max. weight | 2215 kg (4883.24 lbs.) |
| Max load | 655 kg (1444.03 lbs.) |
| Fuel tank capacity | 41 l (10.83 US gal | 9.02 UK gal) |
| Permitted trailer load with brakes (12%) | 1800 kg (3968.32 lbs.) |
| Permitted trailer load without brakes | 750 kg (1653.47 lbs.) |
| Length | 4686 mm (184.49 in.) |
| Width | 1810 mm (71.26 in.) |
| Height | 1442 mm (56.77 in.) |
| Wheelbase | 2840 mm (111.81 in.) |
| Front track | 1588 mm (62.52 in.) |
| Front overhang | 790 mm (31.1 in.) |
| Rear overhang | 1056 mm (41.57 in.) |
| Ride height (ground clearance) | 92 mm (3.62 in.) |
| Approach angle | 13.6° |
| Departure angle | 14.2° |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 9 gears, automatic transmission G-TRONIC |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
Powertrain & Engine Architecture
The heart of the C 300d is the OM 654.920, a 2.0-liter inline-four cylinder diesel engine. This engine is a member of Mercedes-Benz’s modular engine family, known for its lightweight construction and advanced technology. It features a cast iron block with aluminum cylinder heads, and utilizes a two-stage turbocharging system. This setup, combined with a high-pressure common rail direct injection system (operating at up to 2,700 bar), allows for both strong low-end torque and impressive peak power. The engine also incorporates variable valve timing and a cooled exhaust gas recirculation (EGR) system to reduce emissions. The 9G-TRONIC nine-speed automatic transmission is a key component, offering smooth and efficient gear changes. It features a wide gear ratio spread, contributing to both fuel economy and responsive acceleration. The transmission is electronically controlled and adapts its shift patterns based on driving style and road conditions.
Driving Characteristics
The C 300d delivers a refined and capable driving experience. The 500 Nm (368 lb-ft) of torque, available from a low 1600 rpm, provides strong acceleration in everyday driving situations. The 0-60 mph sprint takes approximately 5.6 seconds, making it noticeably quicker than the C 220d. The 9G-TRONIC transmission contributes to a seamless power delivery, and the close gear ratios keep the engine in its optimal power band. While not as overtly sporty as the C 43 AMG, the C 300d offers a good balance of performance and comfort. The rear-wheel drive configuration provides a more engaging driving experience compared to front-wheel drive alternatives, although it can be less forgiving in slippery conditions. The steering is precise and well-weighted, and the suspension provides a comfortable ride without feeling overly soft.
Equipment & Trim Levels
The C 300d typically came well-equipped as standard. Common features included automatic climate control, a high-resolution infotainment system with a central display screen, leather upholstery, and a suite of safety features such as automatic emergency braking, lane keeping assist, and adaptive cruise control. Optional extras included a panoramic sunroof, premium sound system, head-up display, and various driver assistance packages. Interior trim options ranged from aluminum and wood veneers to carbon fiber accents, allowing buyers to personalize the cabin to their taste. The standard seats offered good support and comfort, with optional sport seats available for a more aggressive feel.
Chassis & Braking
The W205 C-Class utilized a multi-link independent suspension system at all four corners, providing a comfortable and controlled ride. The C 300d typically featured slightly stiffer springs and dampers compared to the lower-powered models to handle the increased torque. Braking duties were handled by ventilated disc brakes on all wheels, providing ample stopping power. The anti-lock braking system (ABS) and electronic stability program (ESP) were standard features, enhancing safety and control. The steering system employed an electric power steering system, offering precise and responsive steering feel.
Market Reception & Comparison
The C 300d was generally well-received by automotive critics. It was praised for its refined engine, smooth transmission, and comfortable ride. The fuel economy was also a strong point, with combined figures ranging from 4.9 to 5.4 l/100 km (48-43.6 US mpg). Compared to the C 220d, the C 300d offered a significant performance upgrade, while remaining relatively fuel-efficient. Against rivals like the BMW 330d and Audi A4 3.0 TDI, the C 300d offered a competitive package, with a focus on luxury and refinement. Some critics noted that the ride could be slightly firm on rough roads, and the infotainment system could be complex to navigate.
Legacy
The OM 654 engine family, as used in the C 300d, has proven to be a reliable and durable powertrain. While diesel engines have faced increasing scrutiny in recent years, the C 300d remains a popular choice in the used car market, particularly in Europe. Its combination of performance, efficiency, and refinement continues to appeal to buyers seeking a premium compact executive car. Regular maintenance, including oil changes and filter replacements, is crucial for ensuring the long-term reliability of the engine and transmission. The 9G-TRONIC transmission has also proven to be generally reliable, although some owners have reported minor issues with software glitches. Overall, the C 300d represents a well-engineered and capable vehicle that continues to offer a compelling ownership experience.
