2017-2020 Mercedes-Benz E-class Cabrio (A238) E 350 (299 Hp) EQ Boost 9G-TRONIC

The Mercedes-Benz E-Class Cabriolet (A238) E 350 EQ Boost, produced from 2017 to 2020, represents a sophisticated blend of performance, luxury, and efficiency within the E-Class range. This variant occupied a mid-to-upper position in the Cabriolet lineup, offering a step up in power and technology from the base E 300 models while remaining more accessible than the high-performance AMG variants. It was primarily marketed towards buyers seeking a refined open-top driving experience with modern conveniences and a touch of sporting character. The “EQ Boost” designation signifies the inclusion of a 48-volt mild hybrid system, a key feature differentiating it from earlier E-Class Cabriolets.

Technical Specifications

INTRODUCTION

The A238 E-Class Cabriolet, launched in 2017, represented the fifth generation of Mercedes-Benz’s popular open-top offering. Built on the W213 E-Class platform, it combined the luxurious appointments and advanced technology of the sedan with the thrill of open-air motoring. The E 350 EQ Boost variant, powered by a 2.0-liter turbocharged inline-four engine augmented by a 48-volt mild hybrid system, was introduced as a key model within the range, offering a compelling balance of performance and efficiency. It replaced the older naturally aspirated V6 engines, embracing downsized turbocharging and electrification for improved fuel economy and reduced emissions.

Powertrain & Engine Architecture

At the heart of the E 350 EQ Boost lies the M 264.920 engine, a 1991cc (121.5 cubic inches) turbocharged inline-four cylinder powerplant. This engine utilizes direct fuel injection and a twin-scroll turbocharger to deliver 299 horsepower at 5800-6100 rpm and 400 Nm (295 lb-ft) of torque between 3000-4000 rpm. The key innovation is the 48-volt EQ Boost system. This system incorporates a belt-driven starter-generator (BSG) that provides several functions. It enables a smoother and quieter auto-start/stop function, allows for ‘sailing’ (engine off coasting) during deceleration, and provides a temporary power boost of up to 14 hp to assist the engine during acceleration. The engine features a DOHC (Double Overhead Camshaft) valvetrain with four valves per cylinder. The 9G-TRONIC nine-speed automatic transmission is standard, offering smooth and efficient gear changes. This transmission is electronically controlled and adapts its shift patterns based on driving style and road conditions.

Driving Characteristics

The E 350 EQ Boost Cabriolet delivers a refined and comfortable driving experience. The 9G-TRONIC transmission is well-matched to the engine’s torque curve, providing brisk acceleration. While not as overtly sporty as the AMG variants, the E 350 offers ample power for confident overtaking and enjoyable cruising. The EQ Boost system provides a noticeable, albeit subtle, boost during acceleration, enhancing responsiveness. The rear-wheel drive configuration contributes to a balanced feel, although traction can be limited in wet conditions. Compared to the E 300, the E 350 offers a significant performance upgrade. The manual transmission option available on the E 300 is not offered on the E 350, emphasizing the focus on effortless cruising. The 9G-TRONIC transmission’s gear ratios are optimized for both fuel efficiency and performance, with a tall ninth gear for relaxed highway driving.

Equipment & Trim Levels

The E 350 EQ Boost Cabriolet came well-equipped as standard. Key features included leather upholstery, heated and ventilated front seats, a premium sound system, and a large infotainment display with Mercedes-Benz’s MBUX (Mercedes-Benz User Experience) system. MBUX offered voice control, augmented reality navigation, and a customizable digital instrument cluster. Optional extras included a head-up display, advanced driver-assistance systems (such as adaptive cruise control and lane-keeping assist), and various interior trim options. The Cabriolet also featured a fully automatic fabric soft top, which could be raised or lowered in around 20 seconds at speeds up to 60 km/h (37 mph). Interior color schemes were varied, offering a range of leather and wood trim combinations.

Chassis & Braking

The A238 E-Class Cabriolet utilizes a sophisticated chassis design. Both front and rear suspension systems employ independent multi-link setups, providing a comfortable ride and precise handling. The suspension is tuned to balance comfort and control, offering a composed ride even on uneven surfaces. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power. Anti-lock braking system (ABS) and electronic stability control (ESC) are standard safety features. The Cabriolet’s chassis is reinforced compared to the coupe version to compensate for the lack of a fixed roof, ensuring structural rigidity and minimizing body flex.

Market Reception & Comparison

The E 350 EQ Boost Cabriolet was generally well-received by automotive critics. It was praised for its refined driving experience, luxurious interior, and advanced technology. The mild hybrid system was lauded for its contribution to improved fuel economy and reduced emissions. Compared to the E 300, the E 350 offered a noticeable performance advantage, making it a more appealing option for drivers seeking a more engaging driving experience. However, some critics noted that the four-cylinder engine lacked the character of the previous V6 engines. Against competitors such as the BMW 4 Series Convertible and Audi A5 Cabriolet, the E 350 EQ Boost stood out with its luxurious appointments and advanced technology.

Legacy

The E 350 EQ Boost Cabriolet represents an important step in Mercedes-Benz’s transition towards electrification. The 48-volt mild hybrid system paved the way for more advanced hybrid and electric powertrains in subsequent models. The M 264 engine family has proven to be reliable, and the 9G-TRONIC transmission is known for its smooth operation and durability. On the used car market, the A238 E-Class Cabriolet E 350 EQ Boost holds its value well, attracting buyers seeking a luxurious and technologically advanced open-top experience. Regular maintenance, including oil changes and inspection of the hybrid system components, is crucial for ensuring long-term reliability.