Mercedes-Benz C350e review

The Mercedes C-Class might not be the obvious choice for a plug-in hybrid but the results brook little in the way of argument. Jonathan Crouch reports on the C350e variant.

Ten Second Review

The Mercedes-Benz C350e Plug-In Hybrid is an utter tour de force. Combining a meagre fuel thirst with prodigious power, it returns 134mpg, emits of 48g/km of CO2 and smashes its way to 62mph in just 5.9 seconds. It also represents a seismic shift in power in the compact executive division.

Background

Have you ever sat and watched a sports team that is so ridiculously packed with talent yet never achieves the dominance it should? If you were a car industry reporter at the turn of the millennium, that's the feeling you got watching Mercedes-Benz. Here was a company that, if it could just align its talents, ought to be able to pulverise any semblance of opposition. But it didn't happen. Then things started to change. Quality improved and design became slicker. The AMG performance division started building cars that serious drivers would hanker after. The biggest change was in philosophy. The cripplingly conservative straitjacket that had hindered Mercedes for years was cast aside. The C-Class got really good in 2007 and its 2014 replacement is better again. Now there's a C350e plug-in hybrid version that can dramatically lower your fuel bills. The future's bright.

Driving Experience

As the hybrid badge suggests, there's a petrol engine plumbed into the front of this C-Class, in this instance a 2.0-litre good for 211PS. Granted, that doesn't sound the engine you'd immediately plump for if fuel economy was of prime concern, but this C-Class also offers something when the road opens up and the foot goes down. It's backed up by a 60 kW electric motor that drives the rear wheels and, yes, you can run solely on the electric motor if necessary, for up to 19 miles. Most will just use it for a bit of one-upmanship on the school run or for sneaking on and off the drive at the crack of dawn although those with shorter urban commutes might be drawn to this car. Its more typical use is in city driving, where the petrol engine shuts down when stationary in traffic or at very low crawling speeds and it also acts in parallel on the open road, delivering an additional surge of torque when needed. That means a peak combined power output of 279PS as well as 600Nm of torque. Performance is the rapid side of brisk, the C350e plug-in hybrid jetting to 62mph in just 5.9 seconds on the way to a top speed of 155mph. It'll even crack 80mph on electric power alone. As you might well expect given the fact that you're blending a four-cylinder Mercedes petrol engine with electric drive, the car has been engineered for supreme refinement. The transmission is a seven-speed automatic with an additional clutch between the petrol engine and electric motor.

Design and Build

Aside from the badging, there's nothing that really lets on that this car is a hybrid. It just looks regulation C-Class which is a very good thing. It's tidily executed, with hints of the latest S-Class in its detailing. The long bonnet, a passenger compartment set well back and short overhangs define the C-Class's classic proportions. Large wheels emphasise the rear and communicate a stylishly sporty character. Halogen headlamps are fitted as standard but there are also two LED options offered: a static system and a dynamic version with "LED Intelligent Light System". The interior is confidently styled, with a broad centre console swooping between the front occupants. In automatic vehicles, a large one-piece centre console panel performs an elegant sweep from the centre air vents to the armrest. On vehicles with manual transmission, the centre console is slightly steeper and features two separate trim elements in order to create ample space for ergonomic operation of the shift lever. There's also a free-standing 7-inch central display which or, if you opt for COMAND Online, an 8.4-inch item is specified. Materials quality is much improved and there are some slick details like the five metallic round air vents and the touchpad in the hand rest over the Controller on the centre tunnel. There's even a head-up display option. An extra 80mm in the wheelbase helps rear seats space but packaging the batteries has seen the C-Class saloon's excellent 480-litre boot capacity reduced to 335-litres, or 350-litres if you choose the hybrid estate.

Market and Model

As you might well be aware, Mercedes already sells the C300h hybrid model, which is a more conventional diesel/electric hybrid that doesn't come with a plug socket, and for most buyers that car will meet their needs perfectly well. The C350e plug-in appeals to a slightly different demographic, a little less concerned with hypermiling fuel economy and who just want some serious pace and some sexy technology. Like the S500e plug-in hybrid, the C350e version gets the haptic accelerator pedal that signals to the driver when maximum electric performance has been attained and also sends an impulse through the pedal that signals when the car is being driven inefficiently. Otherwise you're privy to the entire suite of dazzling C-Class technology. The air conditioning system talks to the car's satellite navigation system. When you enter a tunnel, rather than start sucking diesel fumes into the cabin from that labouring artic, the car knows it's entering a tunnel and automatically switches the air conditioning to recirculate, bringing in fresh air only when you've emerge again. The sound system is also worth a mention, utilising the Frontbass system, which uses the space within the cross-member and side member in the body structure as a resonance chamber for really punchy bass response.

Cost of Ownership

The headline numbers take quite some digesting. Mercedes-Benz quotes a carbon dioxide emission of just 48g/km and fuel consumption of 134.5mpg, although they might as well have just plucked these numbers out of thin air. If you have, say a fifteen mile commute to work each day, you're not going to be putting any petrol in this thing all week. Charging? Mercedes claims a relatively brisk recharge time of two hours on regular 240-volt household mains system, although you can shave a bit off that with a higher capacity wall box. The charge status of the battery along with a standard preset air conditioning function can be monitored via the internet. Switching the transmission into ECO mode means that electric motor boost performance is consumption-optimised, and recuperation minimised in favour of coasting distance. The all-electric mode and engine shut-off are activated. 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.

Summary

The Mercedes C350e plug-in hybrid is a dazzlingly clever thing. Nothing this fast and this well-equipped should return these sort of fuel economy figures but somehow it does. The idea of being able to glide back and forth to work past all the rush hour queues at petrol stations is beguiling. In one car you have an eco warrior for the week and a proper tarmac scorcher at the weekend. Clearly this technology will filter down to many more affordable vehicles in due course. That's great news for the environment, reduces our reliance on imports from oil states and delivers savings for motorists. That hybrid cars are now becoming the performance benchmark is also hugely encouraging. Mercedes might have once sat back and watched all this happening. Now they're driving it.