Mercedes-Benz C350e: Practical and powerful plug-in

The plug-in hybrid variant of Mercedes-Benz’ well-regarded compact executive saloon model line, the C350e seems to be the sort of hybrid that would appeal to drivers who are more likely to be ambivalent or lukewarm about hybrids.

Discrete in appearance and badging, and with plenty of conservative appeal, the C350e makes real world performance and efficiency gains on the C250 combustion engine it is based on. More importantly, it does this without too many compromises in terms of practicality, design and driving dynamics and involvement. 

Save for the ‘e’ suffix in its model designation badge, the C350e does without the attention-seeking sense of do-goodery that many a hybrid and electric vehicle exhibit with overt badges, colour schemes and model-specific details, let alone smug, standalone, electrified model lines. Without little to hint at its part-electric drive-line, the subtle C350e is not a car to draw additional attention and passes for a standard combustion engine version of the handsome C-Class, right down to its big front intakes and twin bumper-integrated exhaust ports.

Discrete design

 Smooth, subtle and sleek with flowing lines, sculpted surfacing and a tapered rear, the C-Class’ basic design emphasises its elegance, while avant-garde trim — as tested — layers this with sportier elements, including a two-slat grille with a prominent tri-star emblem embedded within, rather than atop. Unchanged aesthetically, the C350e, however, incorporates an electric motor between the in-line combustion engine and the 7-speed automatic gearbox. Meanwhile its battery pack, situated below the boot floor, reduces boot volume from 480 to 335 litres, and adds a partially stepped and higher boot floor.

Primarily powered by Mercedes’ familiar turbocharged, direct injection, 2-litre, 4-cylinder engine in the same state of tune as the C250, the C350e’s combustion engine develops 208BHP at 5500rpm and 258lb/ft torque throughout 1200-4000rpm. Quick to boost, generous in mid-range and willing to be revved hard, the E350e’s petrol engine is supplemented by an additional 80BHP and 251lb/ft courtesy of the electric motor. Combined, the two motors produce 275BHP and an epic 443lb/ft, which translates into instant response from standstill and huge-ever-present waves of torque for briskly confident driving flexibility.

Flexible, frugal and fast

Swift through gears and versatile on the move, the C350e dashes though 0-100km/h in just 5.9 seconds and is capable of an electronically governed 250km/h when using both petrol and electric motors in hybrid drive mode, where both motors are used when necessary. Using its exclusively electric-drive E-mode, the C350e can attain 130km/h and has a 31km range, while 2.1-litre/100km combined cycle fuel efficiency is quoted in ideal conditions. Undoubtedly frugal, the C350e’s electric range and fuel consumption, however, varies significantly in real world driving and according to conditions and driving style.

Driving the rear wheels through a slick 7-speed automatic gearbox whether driven by either or both motors, the C350e drives like a normal car and can better utilise its electric motor’s capability than EVs with single speed gearboxes. Muscular and genuinely quick in bursts and short sustained full throttle, the C350e is also quick to recharge its batteries through kinetic braking and through the combustion engine, where it serves as an electric generator in charge mode. However, like any hybrid, the C350e is not designed for sustained full-throttle acceleration on incline, where its battery charge depletes more quickly.

Composed and confident

A flexible and practical hybrid that gives the driver a high level of control over how it operates, the C350e’s dedicated hybrid/EV driving mode even includes an E-save mode, where charge is saved for later use according to the driver’s control. Well equipped with driver assistance, safety, convenience and infotainment systems, the E350e also features a haptic accelerator pedal which gives eco-driving feedback for the driver to modulate input for improved efficiency in certain situations. Plug-in charging times quoted by Mercedes include one hour 30 minutes and two hours, 30 minutes for different chargers. 

Confident, quick and composed, the C350e is a highly competent and convincing hybrid. Central to its appeal is how familiar it feels and that it drives and operates much like a regular C-Class in most circumstances. If not an all-out sports saloon with a visceral analogue driver-car connection, the C350e is, however, not aloof, disconnected or synthetic in character. Better integrating the driving experience and its two motors than most hybrids, the C350e’s petrol motor connects to the electric motor and gearbox smoothly through the clutch, while throttle modulation at low speeds is accurate and progressive.

Stable and smooth

A better integrated hybrid than most, the C350e’s throttle response is, however, not as sharp or immediate when coming off the throttle from full load. Quick and versatile, the C350e’s drive-line never feels dependent on its electric motor, and is just fine driving briskly using the combustion engine, despite a significant weight increase over non-hybrid four-cylinder C-Class models. Driving through fast country lanes and switch backs, the C350e’s steering feels as sharp, quick, refined and accurate as other C-Classes, while its regenerative brakes have better pedal feel than many hybrids, and are backed up by yet more effective disc brakes.

Well spaced with a good seating position and elegantly user-friendly cabin, the C350e is also refined and stable at speed, settled on rebound and comfortable over imperfections, as fitted with 225/5R17 tyres. Eager into corners and well controlled throughout, the E350e’s adaptive suspension and driveline could be tailored to emphasise different characteristics, responsiveness and stiffness.

However, it is through quick corners where the C350e’s additional weight of over 200kg is most noticed. With some half of the weight gain positioned behind the rear axle, the C350e does have an instinct to run wide and swing out slightly at the rear if one chucks it in too forcefully or comes back too wild on the throttle, just before stability controls step in.

TECHNICAL SPECIFICATIONS

• Engine: 2-litre, turbocharged, in-line 4-cylinders, +electric motor
• Bore x stroke: 83.1 x 91.9mm
• Compression ratio: 9.8:1
• Valve-train: 16-valve, DOHC, direct injection
• Gearbox: 7-speed automatic, rear-wheel-drive
• Combined power, BHP (PS) [kW]: 275 (279) [205] 
• Petrol engine power, BHP (PS) [kW]: 208 (211) [155] @5,500rpm
• Electric motor, power, BHP (PS) [kW]: 80 (82) [60]
• Combined torque, lb/ft (Nm): 443 (600)
• Petrol engine torque, lb/ft (Nm): 258 (350) @ 1,200-4,000rpm
• Electric motor, torque, lb/ft (Nm): 251 (340)
• 0-100km/h: 5.9-seconds
• Top speed, electronically governed/electric mode: 250km/130km/h
• Fuel consumption, combined: 2.1-2.4 litres/100km 
• CO2 emissions, combined: 48-54g/km
• Fuel capacity: 50-litres
• Electric drive range: 31km
• Charging time, at 230-volt, 16-amp, 3.7kW: 1-hour, 30-minutes
• Charging time, at 230-volt, 13-amp, 3kW: 2-hours, 30-minutes
• Length: 4,686mm
• Width: 1,810mm
• Height: 1,442mm
• Wheelbase: 2,840mm
• Track, F/R: 1,588/1,570mm
• Overhang, F/R: 790/1,056mm
• Aerodynamic drag co-efficiency: 0.27
• Headroom, F/R: 1,039/942mm
• Legroom, F/R: 1,066/812mm
• Luggage volume (without spare tyre): 335-litres
• Kerb weight: 1,785kg
• Steering: Electric-assisted rack & pinion
• Turning Circle: 11.22-metres
• Suspension: Multi-link, air suspension
• Brakes: Ventilated discs, regenerative
• Tyres: 225/50R17