The Mercedes-Benz E-Class Cabriolet (A238, 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 premium open-top segment. Produced from 2021 to 2023, this variant occupied a significant position in the E-Class Cabriolet lineup, offering a compelling alternative to the gasoline-powered models and serving as a step up from the base E 200d. It’s built on the W238 platform, a continuation of the successful E-Class design philosophy emphasizing luxury, technology, and driving pleasure.
Technical Specifications
| Brand | Mercedes-Benz |
| Model | E-class |
| Generation | E-class Cabrio (A238, 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 | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 7.4-7.7 l/100 km (31.8 – 30.5 US mpg) |
| Fuel consumption (extra urban) | 4.6-4.9 l/100 km (51.1 – 48 US mpg) |
| Fuel consumption (combined) | 5.6-5.9 l/100 km (42 – 39.9 US mpg) |
| CO2 emissions | 148-156 g/km |
| Fuel Type | Diesel |
| Acceleration 0 – 100 km/h | 6.6 sec |
| Acceleration 0 – 62 mph | 6.6 sec |
| Acceleration 0 – 60 mph | 6.3 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Emission standard | Euro 6D-ISC-FCM |
| Weight-to-power ratio | 7.4 kg/Hp |
| Weight-to-torque ratio | 3.6 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 | 1970 kg (4343.11 lbs.) |
| Max. weight | 2555 kg (5632.81 lbs.) |
| Trunk space (minimum) | 285 l (10.06 cu. ft.) |
| Trunk space (maximum) | 360 l (12.71 cu. ft.) |
| Fuel tank capacity | 50 l (13.21 US gal | 11 UK gal) |
| Number of gears | 9 |
| Gearbox type | Automatic (9G-TRONIC) |
| Length | 4835 mm (190.35 in.) |
| Width | 1860 mm (73.23 in.) |
| Height | 1430 mm (56.3 in.) |
| Wheelbase | 2873 mm (113.11 in.) |
Powertrain & Engine Architecture
The heart of the E 300d Cabriolet 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. This configuration contributes to its impressive torque output of 550 Nm (405.66 lb.-ft). The ‘d’ designation signifies a diesel engine, and the ‘EQ Boost’ indicates the integration of a 48-volt mild-hybrid system. This system incorporates a 20 hp electric motor integrated into the drivetrain, providing assistance during acceleration and enabling features like coasting with the engine switched off to improve fuel economy. 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 4MATIC delivers a refined and comfortable driving experience. The 265 hp and 550 Nm of torque provide ample power for effortless cruising and confident overtaking. While not a sports car, the acceleration of 0-60 mph in approximately 6.3 seconds is respectable for a luxury convertible. The 9G-TRONIC transmission is well-matched to the engine, providing smooth shifts and keeping the engine in its optimal power band. The 4MATIC all-wheel-drive system ensures excellent traction in all weather conditions. Compared to the E 200d, the E 300d offers a noticeable performance upgrade, while remaining more fuel-efficient than the gasoline-powered E 350 or E 450 Cabriolets. The mild-hybrid system contributes to a smoother start-stop experience and a slight improvement in fuel economy.
Equipment & Trim Levels
The E 300d EQ Boost 4MATIC typically came well-equipped as standard. Features included leather upholstery, heated and ventilated front seats, a premium sound system, a large infotainment screen with navigation, and a comprehensive suite of safety features such as automatic emergency braking, lane keeping assist, and adaptive cruise control. Optional extras included air suspension (AIRMATIC), a head-up display, and various interior trim options. The Cabriolet also featured a fully automatic fabric soft top, available in several colors, which could be raised or lowered in around 20 seconds at speeds up to 50 km/h (31 mph).
Chassis & Braking
The E-Class Cabriolet utilizes a sophisticated chassis design. The front suspension features a multi-link setup, while the rear employs an independent multi-link suspension. This configuration provides a comfortable ride and precise handling. The 4MATIC all-wheel-drive system distributes power between the front and rear axles as needed, enhancing stability and traction. Braking duties are handled by 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, further enhancing safety.
Market Reception & Comparison
The E 300d EQ Boost 4MATIC Cabriolet was generally well-received by automotive critics. It was praised for its refined driving experience, fuel efficiency, and luxurious interior. The mild-hybrid system was seen as a positive addition, improving both performance and economy. Compared to its competitors, such as the BMW 4 Series Convertible and Audi A5 Cabriolet, the E-Class offered a more comfortable ride and a more spacious interior. The diesel engine provided excellent fuel economy, making it an attractive option for long-distance drivers. However, some critics noted that the steering feel could be a bit numb.
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 generally considered to be a durable unit. As a result, well-maintained E 300d Cabriolets are expected to provide years of reliable service. On the used car market, these models hold their value relatively well, particularly those with low mileage and a full service history. The combination of luxury, performance, and efficiency makes the E 300d EQ Boost 4MATIC a desirable option for buyers seeking a premium open-top experience.
