Mercedes-Benz C-Class review

That battery pack is now slim enough to leave the C300e with a flat, rather than stepped, boot floor. But it must be heavy. Our test car couldn’t be weighed on the day of our performance figures, but Mercedes’ own unladen running-order weight is 2005kg, making it some 235kg heavier than a BMW 330e and 166kg heavier than an equivalent DS 9 PHEV (neither of which offers even half as much battery capacity).

For suspension and steering, the C300e differs slightly from other mid-range C-Classes. It is available only from Mercedes’ AMG Line model tier up but does without the lowered sport suspension of other AMG Line derivatives; and instead of sticking with coil springs at both ends, it uses self-levelling air suspension at the rear for closer body control of one of the car’s major masses.

The progressively geared power steering set-up of other AMG Line cars (which can now be combined with four-wheel steering, but only on the forthcoming Mercedes C43 and Mercedes C63 models) is also dispensed with for the C300e; and, irrespective of trim level, it rides on mixed-width 18in alloy wheels of an aerodynamic spoke design, as well as efficiency-minded Michelin Primacy 4 tyres.

Mercedes C-Class comfort and isolation

The C300e is a quiet-riding, well-mannered car at cruise. In comparable test conditions, it recorded better results at both 30mph and 50mph than the DS 9 E-Tense PHEV we tested a few months ago (itself a subjectively pleasingly refined car) with its engine shut down and both wind and road noise quite well contained.

When the engine is running, especially when turning at revs, the story is a little different. At maximum engine revs in fourth gear, the car actually proved two decibels noisier than the DS 9, and noisier too when stationary and with the engine turning over at idle. The hush of the ride can be upset by certain coarser asphalt surfaces, which find a way through to reverberate a little in the cabin. By and large, though, the car is much more often quiet and relaxing than at all uncouth.

The visibility granted from the driver’s seat is good – about typical of a fairly compact saloon with chunky modern pillars, some of which are necessarily close to your eyeline. The primary control ergonomics are sound, seating you low enough at the controls to feel nicely ensconced but high enough to give a good vantage point. A BMW 3 Series feels much more naturally sporting to sit in, but the C-Class marries convenience and comfort with an ideal hip point well.

The driver’s seat itself could be more comfortably cushioned and effectively bolstered, though. Only one seat design is offered in UK-market C-Classes, with either electric (with memory function) or manual adjustment depending on trim level. There is no optional ‘comfort seat’. As they are, the seats offer lateral support that is ultimately less effective than they look fit for, and both shoulder and thigh support could also be improved.

Assisted driving notes

Mercedes uses its advanced suite of active safety systems as a lever to sell its highest-trim-level cars. So if you want a collision avoidance system with pedestrian and cyclist detection, or an adaptive cruise control system that can automatically adapt your speed to the posted limit, or a blindspot monitoring system clever enough to warn you before you open your driver’s door into the path of a passing motorbike? Well, you need to have AMG Line Premium Plus specification, and then add the £1695 Driving Assistance Package Plus on top, making for a rather expensive car.

As standard, however, the C300e gets simpler blindspot warning, autonomous emergency braking and active lane keeping systems that all work fairly unobtrusively and effectively. The lane keeping system reactivates itself with every ignition cycle, and can only be deactivated through the touchscreen, but thereis at least a shortcut to switch it off.