The Mercedes-Benz E-Class Coupe (C238, facelifted in 2020) E 300d EQ Boost 4MATIC 9G-TRONIC represents a sophisticated blend of diesel efficiency, mild-hybrid technology, and all-wheel-drive capability within the E-Class Coupe range. Produced from 2021 to 2023, this variant occupied a mid-to-upper position in the lineup, offering a balance between performance, luxury, and fuel economy. It’s built on the W238 platform, sharing its core architecture with the E-Class Sedan and Cabriolet, but distinguished by its two-door coupe body style and focus on a more dynamic driving experience.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | E-Class |
| Generation | E-Class Coupe (C238, facelift 2020) |
| Type (Engine) | E 300d (265 Hp) EQ Boost 4MATIC 9G-TRONIC |
| Start of production | 2021 |
| End of production | 2023 |
| Powertrain Architecture | MHEV (Mild Hybrid Electric Vehicle) |
| Body type | Coupe |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 7.3-7.7 l/100 km (32.2 – 30.5 US mpg) |
| Fuel consumption (extra urban) | 4.5-4.8 l/100 km (52.3 – 49 US mpg) |
| Fuel consumption (combined) | 5.5-5.9 l/100 km (42.8 – 39.9 US mpg) |
| CO2 emissions | 146-154 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 6.4 sec |
| Acceleration 0 – 62 mph | 6.4 sec |
| Acceleration 0 – 60 mph | 6.1 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6D-ISC-FCM |
| Weight-to-power ratio | 7.2 kg/Hp |
| Weight-to-torque ratio | 3.4 kg/Nm |
| Gross battery capacity | 0.9 kWh |
| Battery voltage | 48 V |
| Battery technology | Lithium-ion (Li-Ion) |
| Electric motor power | 20 Hp |
| Electric motor Torque | 200 Nm (147.51 lb.-ft.) |
| Power | 265 Hp |
| Torque | 550 Nm (405.66 lb.-ft.) |
| Engine displacement | 1992 cm3 (121.56 cu. in.) |
| Number of cylinders | 4 |
| Engine configuration | Inline |
| Fuel injection system | Diesel Commonrail |
| Engine oil capacity | 6.5 l (6.87 US qt | 5.72 UK qt) |
| Kerb Weight | 1895 kg (4177.76 lbs.) |
| Max. weight | 2510 kg (5533.6 lbs.) |
| Trunk (boot) space | 405 l (14.3 cu. ft.) |
| Fuel tank capacity | 50 l (13.21 US gal | 11 UK gal) |
| Length | 4835 mm (190.35 in.) |
| Width | 1860 mm (73.23 in.) |
| Height | 1428 mm (56.22 in.) |
| Wheelbase | 2873 mm (113.11 in.) |
| Number of gears | 9 |
| Gearbox type | Automatic (9G-TRONIC) |
Powertrain & Engine Architecture
The heart of the E 300d EQ Boost is the OM 654.820, a 2.0-liter inline-four cylinder diesel engine. This engine is a highly advanced design, featuring a cast iron block, aluminum cylinder head, and a sophisticated commonrail direct injection system operating at pressures up to 2,700 bar. The engine utilizes a twin-turbocharger setup – a small turbocharger for immediate response and a larger turbocharger for peak power – enhancing both low-end torque and overall performance. The EQ Boost system adds a 48-volt mild-hybrid component, integrating a 20 horsepower electric motor and a 0.9 kWh lithium-ion battery. This system allows for functions like extended coasting, smoother start/stop operation, and a small power boost during acceleration. The 9G-TRONIC nine-speed automatic transmission is standard, offering smooth and efficient gear changes. It’s programmed for comfort and efficiency, but also provides responsive downshifts when needed.
Driving Characteristics
The E 300d EQ Boost delivers a refined and effortless driving experience. The 550 Nm (405.66 lb-ft) of torque, available from a low 1,600-1,800 rpm, provides strong acceleration in everyday driving situations. The 0-60 mph time of around 6.1 seconds is respectable for a diesel-powered coupe. The 9G-TRONIC transmission is well-matched to the engine’s characteristics, providing seamless gear changes and contributing to a relaxed cruising experience. Compared to the E 450 Coupe with its gasoline engine, the E 300d offers superior fuel economy and a broader torque curve, making it more suitable for long-distance journeys. However, it lacks the outright top-end power and responsiveness of the gasoline variant. The 4MATIC all-wheel-drive system provides excellent traction in all weather conditions, enhancing stability and confidence.
Equipment & Trim Levels
The E 300d EQ Boost 4MATIC typically came well-equipped as standard. Features included Mercedes-Benz User Experience (MBUX) infotainment system with a large touchscreen display, leather upholstery, heated front seats, automatic climate control, and a comprehensive suite of safety features such as adaptive cruise control, lane keeping assist, and automatic emergency braking. Optional extras included a premium Burmester sound system, panoramic sunroof, head-up display, and various interior trim options. The interior design emphasized luxury and modern aesthetics, with high-quality materials and meticulous attention to detail. Dashboard configurations were generally consistent across the E-Class Coupe range, with subtle variations in trim and accent colors.
Chassis & Braking
The E-Class Coupe features a sophisticated chassis design. The front suspension utilizes a four-link independent setup, while the rear employs a multi-link independent suspension. This configuration provides a comfortable ride quality while maintaining precise handling. The E 300d typically came equipped with ventilated disc brakes on all four wheels, providing ample stopping power. The electronic stability program (ESP) and anti-lock braking system (ABS) are standard features, enhancing safety and control. The suspension tuning was generally geared towards comfort, but the optional Sport suspension package offered a firmer ride and more responsive handling.
Market Reception & Comparison
The E 300d EQ Boost 4MATIC was generally well-received by automotive critics. It was praised for its fuel efficiency, refined driving experience, and luxurious interior. Compared to other E-Class Coupe variants, the E 300d offered a compelling balance of performance and economy. While the E 450 Coupe provided more power, the E 300d’s superior fuel economy and lower running costs appealed to buyers prioritizing practicality and long-term value. The mild-hybrid system was also seen as a positive addition, contributing to improved efficiency and reduced emissions.
Legacy
The OM 654 engine family, including the version used in the E 300d, has proven to be remarkably reliable. The 9G-TRONIC transmission is also known for its durability. In the used car market, the E 300d EQ Boost 4MATIC Coupe represents a strong value proposition, offering a luxurious and efficient grand tourer at a competitive price point. Regular maintenance, including oil changes and adherence to Mercedes-Benz’s service schedule, is crucial for ensuring the long-term reliability of this powertrain. The combination of diesel efficiency, mild-hybrid technology, and all-wheel-drive capability makes this variant a desirable choice for buyers seeking a refined and practical coupe.
