Mercedes-Benz C350e: Fast and the frugal

c350e_02The irony of having 279hp and 600Nm at your disposal but not the ‘liberty’ to fully deploy them isn’t lost on the two sweaty gentlemen seated behind the nicely sculptured dashboard of the Mercedes-Benz C350e. With ambient temperatures nudging 35-degrees Celsius and the air-conditioning turned off (it was a collective decision), the only consolation was that we were in a white car.

Fuel efficiency contests are more challenging than most people think. How hard can driving relatively slowly be, right? Fortunately, points are awarded for finishing earlier than other competitors within the stipulated timing and route – a 90km-long trip from Mercedes-Benz Malaysia’s spanking new headquarters in Puchong to the Avillion Resort in Port Dickson – so we weren’t exactly hanging about, though we lost count on the number of Kancils overtaking us on the North South Expressway.

Cool exterior belies a cauldron within the cabin, all in spirit of competition.
It’s all about teamwork

It helps that my partner-in-crime and passenger, Thomas of CarSifu, runs marathons for fun and added no more than 70kg of lean muscle to the 1,780kg kerb weight of the C350e. His ability in carrying out monologues (on the subject of durians) meant we didn’t have to switch on the excellent 13-speaker Burmester surround sound system either, thus saving precious electrons, or so it would seem. Every bit counts, I guess.

c350e_08Any hybrid worth its lithium ions delivers optimal efficiency by effectively managing different energy sources (combustion and electric) according to changing driving conditions. In the C350e, there are four operating modes to choose from – Hybrid, E-Mode, E-Save and Charge; most would probably stick with ‘Hybrid’ (the default mode) and let the car decide what’s best. But in the spirit of competition, it wouldn’t be right just letting the system call all the shots, so we tinkered.

There are four hybrid operating modes to choose in the C350e.

The C350e was handed over to us with its 6.2kWh lithium ion battery pack fully juiced up, good for 31 kilometers of zero emission travel according to Mercedes-Benz, at least that’s what the trip computer is showing. Electric propulsion is a highly gratifying experience thanks to the instantaneous response and absence of mechanical vibrations, but tricky city traffic en route to the North South Expressway would soon deplete a third of our precious electric range.

Highway speeds kept between 90km/h to 110km/h, combustion engine preferred here for best returns.

As speed has an exponential effect on aerodynamic drag; the faster one travels, the more energy is required, so the logical strategy was to rely on the 2.0-litre turbocharged four-cylinder for cruising on the highway and to preserve just enough battery power for the finishing stretch. We duly selected E-Save mode (which maintains the state of charge) and settled on a steady cruise varying between 90km/h to 110km/h.

Steady as she goes

At part throttle and in the most docile of Drive settings (E, or Economy), the C350e cruises near silently, its slippery silhouette (0.24cd factor) returns little wind noise. The refinement is also a testament to how well the hybrid drivetrain – 211hp/350Nm combustion engine, 80hp/340Nm electric motor and seven-speed automatic – handles the constant cycles of coupling and decoupling of the engine from the transmission, its workings almost imperceptible even if the Comand display is showing otherwise.

The C350e is capable of a maximum speed of 130km/h on pure electric mode; EV range tops out at 31km.

The aptly named ECO Assist function further guides the driver via haptic feedback in the form of increased resistance and pulses on the drive-by-wire throttle to signal the threshold where the engine would fire up, and when to throttle off so that the C350e can ‘sail’ or ‘coast’ unpowered (engine decoupled state), and for the system to reclaim as much energy as possible. It even decelerates the vehicle automatically if the front radar senses a slow-moving vehicle. I reckon this isn’t how a C350e is driven typically, but you can be a scrooge when you feel like it. Today happens to be a good day.

c350e_10Flirting with the Hybrid mode meant some electricity were spent along highway inclines. And as we exited the Seremban-Port Dickson highway, navigation tells us that we are six kilometers from our destination, with the trip computer showing a corresponding six kilometers’ worth of battery power left. It would seem that the brain-frying heat hadn’t blunted our ability to count.

Mission accomplished

As we pulled into the resort parking, the driver’s display is telling us to charge the vehicle. A quick check on the battery status on the main display reveals a residue charge of 15% (note that the state of charge is rarely allowed to fall any lower to preserve the lifespan and wellbeing of the lithium ion batteries), we could have possibly gone a kilometer or two further on electric but to finish without the combustion engine springing back to life is an encouraging sign. We are also the first to reach the destination out of the five competing teams, surely some points are already in the bag.

Gently does it: eking out what’s left in the battery pack en route to the final destination (and holding up traffic).

The trip computer reveals some pretty impressive numbers. We had clocked 90km over one hour and 22 minutes, in an average speed of 65km/h; more than half the journey (48km) was completed with the engine turned off. Our fuel consumption read 4.2L per 100km, or 23.75km per litre, with the fuel gauge still registering a full tank of petrol.

Distance completed 90km, more than half (48km) of which with the engine decoupled (switched off).
What does this mean?

It’s no coincidence that a slew of plug-in hybrids such as the Mercedes-Benz C350e, BMW 330e and even the Volvo XC90 T8 all share an unbelievable fuel consumption rating of 2.1L/100km (or 47.6km/l) under the NEDC (New European Driving Cycle) combined cycle. While NEDC is irrefutably outdated, it is not a ruse used by manufacturers to hoodwink customers as prevailing regulations governing emissions and fuel consumption are still predicated on the lab-based NEDC cycle. A more stringent standard known as the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) will be implemented later this year in Europe and other parts of the world, so expect current fuel consumption numbers to vary significantly once WLTP is implemented across the board.

Turbocharged 2.0-litre four-pot combines with electric motor for a total system output of 279hp and 600Nm.

Suffice to say, replicating 4.2L/100km will be tough for the average C350e user, but this fuel economy challenge is proof that it can be achieved by mere mortals given best practices such as externally charging the vehicle before a trip are adhered to. If you want to maximise efficiency, make full use of the ‘plug-in’ portion of your PHEV, even if the C350e has the capability to fully recharge its battery pack via the on-board generator driven by the combustion engine, though overall efficiency will suffer inevitably given that the engine has to propel the car and generate charge at the same time.

Full charge via a standard wall socket (at 13 amps) takes around two hours for the C350e’s 6.2kWh battery.
Conspicuous consumption meets conspicuous frugality

At a shade under RM300,000, the Mercedes-Benz C350e is the top dog of the locally assembled C-Class line-up in Malaysia. It’s also the fastest, most frugal and most well-equipped C-Class variant (bar the C63 AMG) featuring Airmatic Dynamic Handling suspension as standard – the only car in the class to offer air suspension. It is the complete package in every sense of the word.

Fast and the frugal: the C350e will do 0-100km/h in under six seconds.

Free from the shackles of conspicuous fuel conservation, Thomas the durian lover takes over the wheel for the return leg, he gives it the full beans, or should I say, the full Musang King. The C350e answers with a mix turbocharged grunt assisted by occasional bursts of electric boost (the customer version of KERS if you will); this a properly fast sedan.

At unpublishable speeds that would otherwise be uncomfortable for any right-minded passenger to bear, the Airmatic suspension keeps the C350e solidly planted despite the erratic dips and crests encountered on your typical stretch of Malaysian engineered highway. Thomas has a grin on his face, and why not since he’s having a lot more fun than I did coaxing miles out of petrol fumes, drenched in perspiration. Little did we know then, we were also on our way back to the Mercedes-Benz Malaysia’s headquarters to collect our winning prize.

The winning car among a motley crew of auto hacks (clue: Thomas is the thinnest one)

Mercedes-Benz C350e
Price: From RM289,888 (w/o insurance)
Engine: 2.0-litre, turbocharged inline-4, RWD
Output: 211hp @ 5,500rpm, 350Nm @ 1,200-4,000rpm
Electric output: 80hp, 340Nm
System output: 279hp, 600Nm
Transmission: 7-sp auto w/shift paddles
Performance: 0-100km/h in 5.9 seconds, top speed 250km/h
Fuel efficiency: 2.1L/100km or 47.6 km/l (combined cycle)
Electric range: 31km
Battery capacity: 6.2kWh
Wheels/tyres: 19in alloys, 225/40 R19 (F) / 245/35 R19 (R)
Safety: 7 airbags, Electronic Stability Control
Warranty: 4 years unlimited; 6-year/100K km for high voltage battery and hybrid components