The Mercedes-AMG Formula 1 team worked with the C-Class development team to introduce a new turbocharger with better responsiveness and efficiency. Combined with the electrical assistance, this helps the petrol car achieve a WLTP average of between 36-46mpg, depending on specification, while emitting 141-180g/km of CO2.
There are three diesel options, each using an updated version of Mercedes’ 2.0-litre unit, which has been boosted in capacity by 42cc. The entry-level C200d makes 161bhp, the mid-level C220d produces 197bhp and the top-rung C300d has 261bhp while also being the quickest variant from rest to 62mph, at 5.7sec. The diesel car is capable of a 57.6mpg average, and emits 131-152g/km.
The C200, C300 and C220d are each available with Mercedes’ 4Matic four-wheel drive system. This can send more torque to the front axle than before for improved dynamics, weighs less and is more frugal, thanks to reduced friction in the transfer case.
A nine-speed automatic gearbox is now standard fitment on all models, in line with Mercedes’ plan to gradually phase out manual gearboxes, and is said to be lighter and more efficient than the previous unit.
The “significantly more electric” plug-in hybrid C300e will be reintroduced to the range shortly after launch, upping the WLTP-certified electric-only range from 34 miles to 62 miles courtesy of a new 25.4kWh battery pack, up from 13.5kWh, which is mounted under the boot floor.
Using a 126bhp permanently excited synchronous electric motor and a 198bhp petrol engine, the C300e packs a combined 304bhp and 406lb ft, making it “not only very efficient but also decidedly sporty”.
It can operate on electricity alone at speeds of up to 87mph and can be charged in as little as 30 minutes with a 55kW fast charger (although an 11kW device is fitted as standard). It also benefits from an adjustable energy recuperation system that can top up the battery at up to 100kW when coasting or decelerating.
This PHEV also gains a hybrid-specific route-planning function that uses the sat-nav, topography and traffic data to map out the most efficient route, enabling, for example, automatic prioritisation of the electric motor in urban areas.