Diesel hybrid: 306 hp Mercedes C 300 de mixes hybrid and diesel advantages

Against all odds, Mercedes offers for its restyled C-Class a new diesel hybrid rechargeable (plug-in) version combining an electric motor with a diesel engine. Meet the Mercedes-Benz C 300 de with 306 hp. 

In terms of hybridization, the Mercedes C-Class will have really, really tried everything … Before its restyling, the German mid-size sedan family offered the choice of a plug-in hybrid gasoline version (211 hp from its 2.0 liter turbo engine + 82 hp from the electric motor) or a conventional hybrid using a diesel engine (204 hp + 27 hp).

Mercedes-Benz C 350 e review: Electrifying luxury

On the occasion of its evolution, the 2.0-liter C-Class C 200 gasoline with 184 hp is now using a mild-hybrid technology (a 14-hp alternator-starter supplies a 48V network), while the hybrid-rechargeable version is converted to a new … diesel formula. An amazing strategy in this period of “diesel-phobia”, and one trully abandoned by all the manufacturers who had tried the combination of diesel and electricity: PSA (3008, 508 and DS5 HYbrid4), Volvo (V60 Plug-In), Audi (Q7 e-tron ).

The technical data sheet of Mercedes’ new C 300 de plug-in hybrid diesel : 306 hp of total system output power (combined torque 700 Nm), thanks to the alliance of its four-cylinder 2.0-liter diesel with 194 hp (OM 654 family, peak torque of 400 Nm) and the 122 hp (90 kW) electric engine. The 0 to 100 km / h sprint would be covered in 5.6 s (5.7 s for T-Modell), while Mercedes announces a range of 57 km in the 100% electric mode (130 km/h max speed) with a mixed gasoline consumption of 1.4 to 1.6 l / 100 km and emissions of 38 to 42 g CO² / km. This is the equivalent to a combined electrical consumption of 19.1-18.7 kWh/100 km. Future owners can thank Mercedes for opting for a new lithium-ion battery of large capacity: 13.5 kWh.

For regeneration of the particulate filter, the combustion engine must run for long enough and with a sufficiently high exhaust gas temperature, while a plug-in hybrid is at its most effective when operation of the combustion engine is minimised. The Mercedes-Benz diesel plug-in hybrids therefore have a partial burning-off strategy in which the particulate load trapped in the filter can be burned off in portions when conditions are suitable for this. In this case, the electric motor can even specifically increase the load for the combustion engine to achieve the exhaust gas temperature necessary for regeneration. The electricity generated in this process charges the high-voltage battery for the next bout of emission-free driving.

In authentic Mercedes, the C-Class retains an automatic transmission controller (nine-speed 9G-Tronic) located behind the steering wheel. It allows to clear a large storage area in the center console. With the restyling, the central screen also expanded (now 10,2-inch) and the classic speedometer and rev counter havereplaced their needles with a 100% digital display. The GPS and multimedia system is still accessed via the center rotating wheel-controller.

There is also one small caveat: poor integration of its batteries, which form a step in the trunk and reduce its volume to only 315 l.

The battery recharge time is estimated at between 2 hours when opting for a 32A Mercedes Wallbox (from 10 to 100 percent SoC State of Charge in approx. 1.5 hours) and 7 hours from a standard household outlet. The on-board charger has gone from 3.6 kW to 7.4 kW (water-cooled) with the restyling. What remains a big unknown: the prices. Before the facelift, the 350 e C-Class T-Modell (petrol) started at 56,300 euros.

Technical data