48 V technology for the E-Class Coupé and Cabriolet: New engine, additional models and even more equipment

Oct 26, 2017

A newly developed four-cylinder petrol engine boasting the performance of a high-capacity six-cylinder engine yet with significantly reduced fuel consumption is set to celebrate its world premiere in the E‑Class Coupé and Cabriolet. The engine generates 220 kW/299 hp from a displacement of 1991 cc and in the E 350 Coupé achieves a fuel consumption (combined) of 6.7 l/100 km (combined CO2 emissions: 149 g/km), while in the E 350 Cabriolet its fuel consumption (combined) is 6.8 l/100 km (combined CO2 emissions: 154 g/km). Pioneering technologies such as the EQ-Boost starter-Generator, 48 volt on-board electrical system and a particulate filter for petrol engines contribute to enhanced environmental compatibility. The basic price for the new E 350 Coupé is 59,738 euros, and for the E 350 Cabriolet 65,212 euros (incl. VAT in each case). New highlights for individualisation are available with immediate effect: these include new paint finishes and trim parts, a Night package for the Cabriolet, plus ENERGIZING comfort control which can help to enhance the well-being and performance levels of the occupants. In addition, in future drivers will even be able to make use of specific office functions directly in the vehicle and also access important data if required – almost as if they were in their office.

With its new high-tech combustion engine in the E-Class Coupé and Cabriolet, Mercedes-Benz is systemically continuing its CASE strategy which through the areas of networking (Connected), autonomous driving (Autonomous), flexible use (Shared & Services) and electric powertrains (Electric) is designed to turn the car into a platform for future mobility concepts and a space that offers a digital experience (for more information see page 8). A key step in this is the introduction of a new four-cylinder petrol engine featuring a specific output in excess of 100 kW and an intelligent combination of state-of-the-art engine technology and partial electrification through 48 V technology. With an output of 220 kW/299 hp and maximum torque of 400 Nm, it is pushing forward into performance areas which were previously the reserve of our high-capacity, six-cylinder engines. At the same time, it consumes significantly less fuel than corresponding six-cylinder engines (for more technical details see page 6). The innovative 9-speed 9G-TRONIC automatic transmission supports both a dynamic and a fuel-saving driving style.

High performance with the characteristics of a hybrid

The engine's special features include twin-scroll turbochargers, belt-driven 48 V starter-alternator (EQ Boost) and electric 48 V water pump. In conjunction with the modern on-board 48 V technology, the starter-alternator enables outstanding efficiency by making hybrid functions available. In practical terms these are seen in such features as

  • easy start, in which the engine starts and accelerates almost imperceptibly,
  • boost – this function can support the combustion engine in the engine speed range up to 2500 rpm with additional output of up to 10 kW and 150 Nm of torque from the electric motor,
  • recuperation of up to 12 kW when braking,
  • operation within favourable engine characteristics,
  • gliding with automatic engine switch-off when the driving conditions permit this.

Further new additions to the E-Class Coupé and Cabriolet range include the model E 220 d 4MATIC (fuel consumption (combined) for Coupé [figures for Cabriolet in square brackets]: 4.8 l/100 km [5.1 l/100 km]; combined CO2 emissions: 126 g/km [133 g/km]), plus the E 200 4MATIC (fuel consumption (combined) for Coupé [figures for Cabriolet in square brackets]: 7.0 l/100 km [7.3 l/100 km]; combined CO2 emissions: 158 g/km [164 g/km]). 

The new models


E 220 d



E 200 4MATIC Coupé

E 350


E 220 d



E 200 4MATIC Cabriolet

E 350 Cabriolet








Displacement (cc)







Rated output








Additional electric boost output (kW)







Torque (Nm)







NEDC consumption

(l/100 km), comb.







Comb. CO2 emissions (g/km)







Efficiency class








0-100 km/h (s)







Top speed (km/h)







* Electronically limited

Even more individual

In addition to the extended model range, the E-Class Coupé now also offers additional highlights for individualisation. New features include two paint finishes in rubellite red and diamond silver as well as light longitudinal-grain aluminium trim elements.

The E-Class Cabriolet can be given a particularly sporty touch with the optional new Night package. It comprises:

  • front bumper or AMG front apron with trim element in high-gloss black,
  • diamond radiator grille with integral Mercedes star and single louvre in high-gloss black,
  • exterior mirror housings in high-gloss black,
  • chrome trim element in the rear bumper in high-gloss black,
  • depending on standard equipment, 18-inch 5-twin-spoke light-alloy wheels, painted in black with a high-sheen finish, or 19-inch 6-spoke light-alloy wheels, also painted in black with a high-sheen finish, with mixed-size tyres, or in conjunction with the AMG Line exterior, 19-inch AMG 5-twin-spoke light-alloy wheels, painted in high-gloss black with a high-sheen finish, with mixed-size tyres, optionally 20-inch AMG multi-spoke light-alloy wheels, painted in high-gloss black with a high-sheen finish. 

Even when it comes to the vehicle key, both the Coupé and Cabriolet boast a focus on individualisation. As such there is a choice of high-gloss vehicle key in white or black with decorate frame in either high-gloss chrome or matt chrome (only for the white variants).

Also new is the Comfort Connectivity package. It provides users of Mercedes me with the advantages of special services in the areas of maintenance and convenience. Furthermore, it provides support with Accident Recovery and Breakdown Management. And with the Concierge Service there is always a personal assistant to hand.

SMS notification in the event of parking damage

The functions of the Anti-Theft Protection package have also been extended. While previously being able to sound an alarm in the event of unauthorised entry into the vehicle interior or a change in the vehicle position, now the sensors are also able to detect when another vehicle touches the vehicle, for example when manoeuvring. In such a case it notifies the driver or owner immediately about possible parking damage by sending an SMS message to a predefined mobile phone number.

On-board wellness and fitness programme

Like the S-Class, the Saloon, Estate, Coupé and Cabriolet models of the E-Class also provide ENERGIZING comfort control as an option. Developed by Mercedes-Benz, this optional extra links various comfort systems in the vehicle, including climate control, ambience lighting, massage and fragrancing functions, and allows customers to configure a specific wellness set-up to suit their mood or needs. This enhances physical comfort and performance on the road. ENERGIZING comfort can be experienced in all seats, depending on the equipment level.

Six perfectly coordinated programmes are available to choose from:

  • Freshness
  • Warmth
  • Vitality
  • Joy
  • Comfort
  • Training (three training modes – muscle relaxation, muscle activation and balance – each with several exercises)

The programmes all run for ten minutes. They are visualised on the media display with colour graphics, and backed by suitable music.

In-Car Office: the office goes mobile

With the "Office function in the car" service, the driver and front passenger of an E-Class can now use certain office functions directly in the vehicle and access important data – almost as if they were in their office. For example, the service uses the locations of calendar entries and automatically transfers these to the car's navigation system. The user can also dial into a telephone conference on the basis of a calendar entry. The system automatically detects the required PIN access code and simultaneously dials it.

The intelligence required for the service is stored directly in the infotainment system of the vehicle and in the backend. The vehicle just needs to be equipped with COMAND Online and have an active data connection. 

Under the microscope

New M 264 four-cylinder petrol engine: sporty specific output

Mercedes-Benz is bringing to the road a new generation of combustion engines featuring pioneering technologies. These include a four-cylinder petrol engine boasting high efficiency which benefits environmentally friendly power delivery.

A key member of the comprehensively redeveloped engine family from Mercedes-Benz is the new four-cylinder petrol engine with a specific output in excess of 100 kW. It advances into output regions which were previously the reserve of our high-capacity six-cylinder engines. At the same time, it consumes significantly less fuel than a corresponding six-cylinder engine. The engine's special features include twin-scroll turbochargers, belt-driven 48 V starter-alternator (EQ Boost) and electric 48 V water pump.

Spontaneous output at any time

In the interests of high power output and a spontaneous engine response, Mercedes-Benz has opted for twin-scroll turbocharging. Unlike conventional systems, a twin-scroll turbocharger merges the exhaust gas ducts of cylinder pairs in the flow-optimised manifold. This turbocharging concept with systematic cylinder flow separation produces high torque in the low rpm range together with high specific output.

A further-improved intake manifold with extremely short air paths and an exceptionally compact compressor housing additionally ensure spontaneous engine response and a fast reaction to accelerator pedal movements. The twin-scroll turbocharger has an electric wastegate actuator, which allows fast changes of the charge-air pressure.

To reduce exhaust emissions, use is made of tried-and-tested piezo injectors with a good mixture preparation, a further-improved combustion chamber and a particulate filter for petrol engines. Further efficiency measures include intake CAMTRONIC and a friction loss reduction package.

Key technical data


M 264

No. of cylinders/arrangement


Displacement per cylinder, cc


Total displacement, cc


Cylinder spacing mm


Bore mm


Stroke mm




Connecting rod length mm


Rated output, kW/hp

220 /299 at 5800-6100 rpm

+10 kW via EQ Boost starter-alternator

Peak torque, Nm

400 at 3000-4000 rpm

Compression ratio


48 V electrical system and starter-alternator enable hybrid functions

In the E-Class Coupé and Cabriolet, the new petrol engine is combined with a 48 V electrical system, which is used for the belt-driven starter-alternator (EQ Boost) and the electric water pump. The fundamental advantages of a 48 V on-board electrical system: it offers four times the power of a 12 V system at identical currents, but avoids the additional safety architecture of a high-voltage electrical system.

Furthermore, in conjunction with the belt-driven starter-alternator, the 48 V on-board electrical system enables the key hybrid functions of "recuperation", "boost" and "coasting" to be implemented for the first time without high-voltage components. As a result, significant fuel savings are made possible.

The belt-driven starter-alternator is coupled with the internal combustion engine in a manner similar to how the alternator is commonly connected. The system therefore uses existing generator mounting points and does not interfere with the design of the powertrain. In addition, such a starter concept is so durable that the engine can be switched off much more often and whenever it is not needed: whether during decelerating or coasting, i.e. when rolling to save fuel at higher speeds, as soon as drivers take their foot off the accelerator.

Apart from reduced fuel consumption and CO2 emissions, the 48 V on-board electrical system also brings about increased comfort. This comes as a result of the 48 V on-board electrical system being able to crank the internal combustion engine to idle speed very smoothly. This benefits NVH (noise, vibration, harshness) and the transition when the engine starts is even quieter: the engine restarts as if it had never been off.

The integration of a 48 V on-board electrical system also offers advantages for further functions in the vehicle in future. On account of the higher voltage, the same power requires only a quarter of the current of a conventional system. This means that the wiring may be thinner and thus lighter – which indirectly contributes to saving fuel. The 48 V on-board electrical system also paves the way for the further expansion of infotainment and assistance systems.

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