Mercedes-Benz C 300 e Tested: Truly Next-Gen PHEV
A new C-Class PHEV means more power, more range, and a new battery. So how does the all-new Mercedes-Benz C300 e add up? Let's find out!
In the relentless race for less CO2 emissions, Daimler has updated a key player in its contribution to this global effort. All hail the Mercedes-Benz C 300 e! And this isn't just another halo project, no as the C-Class is a large volume model, these cars are making a significant impact on bringing the CO2 figures down. So the need to get this right is big with regulations getting ever stricter and the consumers growing ever more demanding when it comes to the performance of PHEVs. So how did Mercedes-Benz go about this? From the first steps in the development of the new C-Class, it also housing a PHEV drivetrain was taken into account. No new trick slammed into an existing car. No, this is a thouroubred PHEV. And boy does it show! And from previous tests, we know the C-Class is a monstrously good car (read about the C 300d here). And you guessed it, these add up quite tastefully in this 330 horsepower and 550 Nm PHEV that can hit 0-100 kph in 6.1 seconds.
What's new?
If I was really lazy, I'd just sum up the changes in the new C 300 e like this: it gets a bigger battery, it has more range (100km WLTP), gone is the weird battery hump in the luggage compartment, and it charges quicker. All of this is true but the effort put into this doesn't reflect in these words. As I wrote earlier, the new C-Class PHEV is a thoroughbred that developed like that from the start. In this lies the base for many of the improvements Mercedes-Benz has achieved compared to the previous C 300 e. And at the base of all these improvements lies one abstraction: effiency. If you'd read the press release on this car, you'll see just how deep this abstraction runs in the development of this PHEV.
I'm not taking you that deep into the all-new C 300 e though, but I'll take you for a short stroll through it. For starters, the integration of the 129 horsepower and 440 Nm synchronous motor into the transmission is something new. Benefits here include compacter packaging but also in terms of driving there are improvements because of this approach. The electric motor being placed here allows for the smooth overtake of the petrol engine at speeds above 140 KPH when the electric engine slowly fades out. Alongside this, the high-voltage (HV) battery has been updated. This means its weight-to-capacity ratio has dropped and it now offers 25.4 kWh. To cope with the increased charge speeds, the C 300 e can take an optional 55 kW DC, and higher energy demand of the drivetrain, a new cooling system runs through the battery. Mercedes-Benz has also improved the heating function to get the battery warm enough to reach 55 kW speeds. Despite the rush for efficiency, weight has increased and now comes in at 2.080 kilograms. To cope with this, air suspension at the rear is standard for PHEV variants of the C-Class.
How did Mercedes pour all this into a C-Class?
When you enter the cabin there’s no clue that you’re inside a PHEV version of the C-Class. There’s just a slight hint for those paying close attention to what’s happening on the screens, as the dashboard now shows ‘ready’ after pressing the car its start button. This clue of its electric nature is a nice bridge to what the entire experience in the new PHEV C is like: the majority of things in the C-Class are just like in any non-PHEV C-Class. Only details show the difference. And sure, the drivetrain is vastly different from those we tested earlier. But it's still like any Benz, offering quality throughout and in an easy-to-use package. No difficult settings, no science fiction at all. You just get in and drive off, albeit electrically, like any other vehicle you’re used to.
Every time you start, the car automatically slips back to its EV-mode (unless you change that setting). That means, unless you choose to navigate via the MBUX navigation and put the car in Hybrid mode, the car will drain the battery first before tapping into the fuel tank. Don’t want that? Then slipping into ‘battery hold’ mode is as easy as switching a drive mode. Why? Cause it is a drive mode! This logical approach to operating the drivetrain in the C 300 e also reflects how Mercedes-Benz designed the recuperation controls, which are the shifting paddle you're used to. In any other driving mode than Sport, these operate the level of recuperation. And with the new architecture that allows for higher power flow throughout the system, this generation of PHEV has enough recuperation power to allow for one paddle driving in the strongest recuperation mode. There’s also an automated mode for power recovery but this just doesn’t seem to work in the city as deceleration before intersections aren’t initiated by this system. A shame? Maybe, but this would demand a large amount of computing power. Maybe the next generation can pull this off?
How does it add up?
To put it simply: having this level of electric range in a PHEV is a game-changer, especially with the three-phase charging the C 300 e facilitates. The range claimed by Mercedes-Benz is easily met, and thus the 100-kilometer mark was met several times during the time I had the car. In the whole week of driving it, I clocked around 1000 kilometers and ended up using just a quarter of the fuel tank. This is a testimony to how little need there was to use the additional range or power. I would have never clocked this many electric kilometers if the driving experience was terrible using just the electric drivetrain. Due to the low-level torque on offer, there's enough sensation in the accelerations even without them being that swift in pure numbers. And another big plus here is the calibration of the throttle. Mercedes-Benz calibrated it in the C 300 e in such a way that only after a relatively deep push, all torque is unleashed. So a gentle push really is a gentle acceleration and a heavier push follows the same logic.
Add the silence of the electric drivetrain, and the C-Class offers a new level of peaceful bliss. This bliss is interrupted the moment the kick-down of the throttle pushes the M254 petrol engine into play. During swift engagement, the engine noise entering the cabin is unpleasantly loud. This has to do with the contrast of the silence and it disappearing rapidly, a contrast noticeable when the switch is more gentle. Say above a 140 kph for example, the electric engine slowly opts out of the game as the petrol engine takes over. During this process you barely notice it happening. But as speed is lower and so is road-noise, so is the rush in which the petrol power is summoned, and so does it erode on the harmony in play between the drivetrains. This brings us to the Sport mode, a mode in which the C 300 e supposedly shows the dynamic nature Mercedes-Benz intended to house inside the PHEV setup. I'll kill the dream right away: there's no sportiness here. Why not? It isn't the most rewarding sensation when the 4-cylinder engine sounds tortured all the time and the increase in the sensation of acceleration isn't significantly enlarged along with it. Sport mode seems to hold no true value in the car, it seems a mere gimmick to switch on during a bad and moody day where you want to destroy things. Things like your wallet and the range. Want the electric range back quickly? Mercedes-Benz offers the DC-charging as an option, even on the € 61.831 AMG-Line. When all energy is drained from the battery, the C 300 e still puts down a consumption average of 4.5l/100 km.
Why!?
Mercedes-Benz has without a doubt in my mind created the next-gen of entry-level luxury PHEVs. The seemingly invisible integration of the PHEV drivetrain into their C-Class makes for very few sacrifices for buyers compared to the sole-ICE C-Class models. The added benefits for the C 300 e show will vastly outweigh the minute sacrifices for many drivers. Drivers who seek a tranquil and luxurious form of transport will be more than satisfied with how this car performs in the real world. From decent electric range to genuinely quick charging, the new C-Class PHEV takes it to the next level. But buyers hoping the C 300 e would offer a sporty experience should look elsewhere.
