E is one of the major concerns of automakers in the fact that a sack of rice falls over in China. If it tipped onto a main artery of one of the many Chinese megacities, cars would have to brake. And by the time someone has finally cleared away the sack, the chain reaction could possibly result in an enormous traffic jam that leads to traffic collapse. Gasoline engines then snorted exhaust gases into the already smoggy sky for hours. The next morning, the mayor simply closed the city to all cars that weren't entirely electric.
Exaggerated? It is not, but rather exactly the scenario that BMW boss Harald Krüger predicted when visiting the editorial office. And that's why there are plug-in hybrids like the Mercedes C 350 e and VW Passat GTE. They drive purely electrically in the standard cycle of 31 or 50 km, which would be exempt from driving bans, as any Chinese or even French or German city could issue. In addition, they want to be the smartest form of electric mobility. With us, almost all e-cars are second cars and only run short distances. A car with a combustion engine is available for long journeys. The C 350 e and GTE, which are also available as station wagons, want to be able to do both. Can you do it?
Networked from battery to navigation system
Let's first clarify the technology of the plug models. In the C 350 e, the 211 hp two-liter turbo gasoline engine and the 60 kW electric motor positioned in the so-called hybrid head of the automatic transmission work together. Together they have a system output of 279 hp and a total torque of 600 Nm. In the GTE, the 1.4-liter turbo gasoline engine with 156 hp and the 85 kW e-machine with 218 hp and 400 Nm complement each other. In the VW, too, the electric motor is positioned on the gearbox - in the housing on the input shaft between the dual-mass flywheel and the separating clutch to the gasoline engine. Both Mercedes and VW store the energy for the electric motors in lithium-ion batteries. They are each positioned above the rear axle, and because they are tall, they take up a third of the trunk volume in both cases.
The batteries can be charged from a wallbox or a normal 230-volt socket. With the Passat with the 9.9 kWh battery, this takes two and a half to four and a quarter hours. The battery in the C-Class regains its 6.4 kWh after just under two or a good three hours. And while we are now theUnplug the charging cable, loop it together and stow it in the trunk, there is time to deal with the networking of the on-board systems. Both cars use GPS data to optimize the drive. The control system plans a gradient in order to recuperate, i.e. to use the electric motor as a generator that feeds energy back into the battery. If a GPS route guidance ends in a city, the control system retains enough battery reserves to be able to drive purely electrically from the city limits. In other modes, the driver can also choose whether he wants to drive purely electrically, charge the battery or maintain their energy level.
Mercedes C 350e with intelligent recuperation
Of course, both slow down when pressure is applied on the brake pedal initially only through recuperation to recover energy. The brakes only help with stronger pressure, although the pedals cannot be adjusted very precisely on both. Clever on the other hand: The Mercedes uses data from the collision warning and emergency braking system. If the Mercedes C 350 e gets too close to a vehicle in front, it initially decelerates not with the brake, but with recuperation. In addition, the seven-speed automatic transmission of the Mercedes, like the six-speed dual clutch box of the VW, puts the car into neutral in order to use the momentum.
Perhaps the most remarkable thing is that the driver hardly notices the whole effort. Of course, you have to be prepared for it in order to use the technology effectively. But nobody inadvertently buys the C 350 e, which is 6,000 euros more expensive when the equipment has been adjusted, or spends 9,200 euros more for a Passat GTE than for a similarly equipped 1.4 TSI DSG.
VW Passat GTE with advantages in terms of consumption
Such surcharges can hardly be outweighed by the under-consumption alone, rather with the enthusiasm for these two cars that are always in the Start electric mode. And yet clear differences between the Mercedes C 350e and Passat quickly become apparent. The Mercedes has the more powerful combustion engine, but a weaker electrical power plant. Its 60 kilowatts are quickly overwhelmed by the 1.9-ton limousine. Even on gentle inclines, the combustion engine is activated via the separating clutch (which also replaces the converter) to support it.
It is only possible to drive purely electrically if the topography and driver character are very mild - a maximum of 130 km /h and 23 km. The 350 e does not make the promised 31 kilometers in the test. With an impact on test consumption: according to the auto motor und sport profile, 3.6 liters of super and 10.6 kWh /100 km. This corresponds to 144 g CO2 /km, which is well above the 112 g /km of the Passat, which is calculated from the 1.4 l Super and 14.2 kWh of electricity /100 km. How impressively good this test value is can be seen when we look in our database. 112 g /km corresponds to 4.3 lDiesel /100 km. So far only one car has managed so little in the test, the VW Lupo 1.2 TDI 3L (our old buddy, the three-liter Lupo).
Larger battery in the GTE ensures more electric range
The consumption advantage is also explained by the larger battery capacity. In the test, the Passat almost achieved the standard specification of 50 km purely electric range with 47 km. With the 85 kW electric motor, the GTE starts moving more powerfully, the petrol engine keeps itself out of the drive even at motorway speed. The four-cylinder gasoline engine of the EA 211 series has specially coated main and connecting rod bearings, piston rings, bearing shells and an adapted piston clearance so that it can do this without damage if there are only short journeys over a few weeks that are driven purely electrically. When the 1.400 is switched on via the disconnect clutch, it sounds a bit boomy, but then drives the VW forward spiritedly and efficiently.
To find out how economical the combustion engines are without electric support, we have the Mercedes C 350 e and Passat GTE also sent out on the eco circuit with an empty battery. Here too, the VW was more economical with 5.2 l /100 km. The two-liter in the 350 e needs 6.2 l /100 km, but ensures a more vehement temperament. The C clearly surpasses the urgent performance of the Passat. In addition, with the Airmatic as standard, it offers assiduous suspension comfort, both empty and loaded.
On the other hand, despite the optional adaptive damper, the GTE seems out of balance due to the 125 kilo battery in the rear. More harsh than usual, it responds to bumps, bumps heavily loaded over short waves. Handling and steering are not as precise and direct as with the other models. This one time, the Mercedes looks more precise and agile, has more feedback in the steering. That doesn't change the fact that the more spacious, more economical VW - you guessed it - puts it in the bag.