Mercedes-Benz introduced the C 350 PLUG-IN HYBRID, in both sedan and wagon versions, at the North American International Auto Show (NAIAS). Following the C 300 BlueTEC HYBRID, the C 350 PLUG-IN HYBRID is the second hybrid model in the new C-Class and the second Mercedes-Benz model (following the S 500 PLUG-IN HYBRID) to feature PLUG-IN HYBRID technology. Its four-cylinder gasoline engine, in conjunction with 60 kW electric motor, gives it a total system output of 205 kW (279 hp) and torque of 600 N·m (443 lb-ft).
The all-electric range is 31 kilometers (19 miles); fuel consumption figures is 2.1 liters of fuel per 100 kilometers both versions. This corresponds to CO2 emissions of 48 grams (49 grams for the wagon) per kilometer. Both models are also equipped as standard with AIRMATIC air suspension plus a Pre-Entry Climate Control system that can be controlled via the internet. The C 350 PLUG-IN HYBRID will be at dealerships from March 2015.
The PLUG-IN HYBRID is an investment in the future of Mercedes-Benz and we believe it will become established as the successful technology for maximum efficiency coupled with powerful dynamic performance. We will be launching ten new PLUG-IN HYBRID models up to 2017.—Prof. Dr Thomas Weber, Member of the Board of Management of Daimler AG and responsible for Group Research and Mercedes-Benz Cars Development
For the C 350 PLUG-IN HYBRID, Mercedes-Benz combined this hybrid drive concept for the first time with an efficient four-cylinder gasoline engine. From a displacement of just under two liters, it produces 155 kW (211 hp) and maximum torque of 350 N·m (258 lb-ft). Its direct injection system with spray-guided combustion uses electronically precise controlled multiple injection and fast multi-spark ignition to deliver performance coupled with high efficiency and low emissions.
The electric motor of the C 350 PLUG-IN HYBRID has an output of up to 60 kW and delivers torque of 340 N·m (251 lb-ft).
The hybrid module of the standard 7-speed automatic transmission 7G-TRONIC PLUS incorporates both the electric motor and an additional clutch between the combustion engine and the electric motor. When driving in all-electric mode, this decouples the combustion engine from the drive train. It also, however, offers the possibility of moving off using the combustion engine but with the performance of a wet start-up clutch. The clutch here is a substitute for the torque converter.
The C 350 PLUG-IN HYBRID’s Li-ion battery pack has a capacity of 6.2 kWh. The battery is water-cooled, weighs around 100 kilograms (220 lbs) and is mounted in a sheet steel housing underneath the rear axle in order to maximize crash safety, driving dynamics and trunk space.
The battery can be recharged in around 1 hour 45 minutes at a wallbox or at one of the growing number of public charging points (230 V, 16 A, 3.7 kW single-phase). Depending on the connection, a charge time of around two hours is achievable (with 230 V and 13 A, 3.0 kW).
Despite the space taken up by the battery, the C 350 PLUG-IN HYBRID still has trunk capacity of 335 liters in its sedan format and of 350 in the wagon model, or in the latter case of 1370 liters with the rear-seat backrests folded down and, as ever, a level load compartment floor.
A new feature of the C 350 PLUG-IN HYBRID is the haptic accelerator pedal, which helps to reduce fuel consumption and thus also exhaust emissions. It provides two types of information:
If, when driving in electric mode, the driver’s foot meets a point of resistance on the accelerator pedal, this is an indication that maximum electric performance is being delivered. If the driver continues to depress the accelerator beyond this resistance point, the combustion engine will kick in.
A double impulse from the ECO Assist function signals that the driver should remove their foot from the accelerator pedal in order to switch off the combustion engine and decouple it from the drive train. Assuming that the driver does what the double impulse suggests, the intelligent engine management system of the C 350 PLUG-IN HYBRID will vary the deceleration mode between unpowered (sailing) and recuperation, using data from the car’s radar systems as its basis.
Anyone wanting to can intervene manually and regulate the hybrid interplay themselves, with the help of five operating modes and three transmission modes. This is done via an operating mode switch and a transmission mode switch located in the centre console. A display in the middle of the instrument cluster shows the current setting.
Selecting a specific transmission mode enables the driver to define certain functions that influence the driving experience:
I Individual: individual definition of the characteristics of the transmission mode, including: Drive system; Chassis and suspension; Steering; ECO Assist; and Climate control.
S+ Sport+: maximum boost performance, very sporty gear changes, the combustion engine is always active, particularly stiff suspension and damping settings.
S Sport: enhanced boost performance, sporty gear changes, the combustion engine is always active, stiff suspension and damping settings.
C Comfort: boost performance and recuperation optimised for comfort and consumption, electric drive/ engine shut-off possible up to 130 km/h, comfort-oriented standard settings.
E Economy: boost performance is consumption-optimised, recuperation minimised in favour of coasting distance. All-electric mode and engine shut-off are possible. If the navigation system’s route guidance function is switched on and the Hybrid operating mode selected, the system will control the charge status of the high-voltage battery according to the route, ensuring that the electric operating mode is used as far as possible in built-up areas. The ECO Assist is also active.
ECO Assist activates an additional function, using the radar technology behind the standard proximity warning system in order to do so. If the radar system identifies a slower-moving vehicle ahead, it sends a double impulse through the haptic accelerator pedal to signal to the driver to take their foot off the accelerator. The vehicle will then adjust its deceleration automatically, using the electric motor to do so. In this way frequent braking, particularly in stop-and-go traffic, can be avoided.
In addition to selecting a transmission program, the driver of the C 350 PLUG-IN HYBRID can also use the operating mode switch to influence the regulation between electric mode and the use of the combustion engine for driving. In the Eco and Comfort transmission modes, the following operating modes are available:
Hybrid: all hybrid functions such as electric operating mode, boost and recuperation are available and are applied according to the driving situation and route in the most fuel-efficient manner.
E-mode: used for all-electric driving – for example in inner-city areas or because the battery holds sufficient charge for the remainder of the journey.
E-save: the charge status of the battery is maintained – for example to allow all-electric driving in an environmental zone at a later stage in the journey. Electric driving and the boost function are therefore only available to a limited extent.
Charge: allows the battery to be recharged while driving using the combustion engine – for example in order to ensure a higher state of battery charge for later parts of the journey. The combustion engine remains switched on and fuel consumption may increase. Electric operation is not possible.
In the transmission modes S+ and S, the hybrid operating mode is activated. In the Individual mode, the choice of available operating modes depends upon the drive system setting.
The best strategy for efficient operation is anticipatory driving. If the exact destination is known because the relevant data has been entered into the navigation system, charge and discharge of the C 350 PLUG-IN HYBRID's high-voltage battery are controlled to ensure the optimal use of energy over the whole route.
Another key point is the requirement that urban areas should be reached with a fully charged battery if possible, so that the vehicle can be driven efficiently in stop-and-go traffic – and frequently in electric mode.
The new C 350 PLUG-IN HYBRID offers the familiar range of equipment and appointment options that are available for the C-Class and, in addition, includes the enhanced comfort feature AIRMATIC air suspension as part of its standard specification, along with a further comprehensive range of pre-entry climate control options.
Both variants of the C 350 PLUG-IN HYBRID offer the same range of safety and assistance systems as all other C-Class models. Two of the systems fitted as standard are ATTENTION ASSIST, which can warn of inattentiveness and fatigue, and COLLISION PREVENTION ASSIST PLUS, which protects against collision at speeds of over 7 km/h (4 mph) and, if the danger remains and the driver fails to react, can also undertake autonomous braking at speeds of up to 200 km/h (124 mph) and by so doing reduce the severity of an accident involving a slower-moving vehicle. Further systems from the new S and E-Class, either new or with significantly enhanced functions, are also available as options.