Fuel consumption can be as low as 2.1 litres per 100km, thanks to a 6.2 kWh high-voltage lithium ion battery and hybrid vehicle technology that allows a range of 31km in pure electric mode.
However, in real-world everyday driving, the fuel efficiency of 2.1 litres per 100km is quite impossible to achieve.
Recently, Mercedes-Benz Malaysia organised a fuel economy challenge starring the C 350 e Avantgarde plug-in hybrid, in order to demonstrate its fuel-saving technologies.
The challenge was simple - drive the C 350 e Avantgarde plug-in hybrid on a 90km route from Wisma Mercedes-Benz in Bandar Kinrara to Avillion Port Dickson.
The journey had to be completed within 90 minutes, and extra points were given for the earliest arrivals.
To recap, the Mercedes-Benz C 350 e Avantgarde plug-in hybrid was launched last October priced on-the-road with GST (without insurance) at RM289,888.
It uses a seven-speed 7G-Tronic Plus automatic transmission to manage the familiar 2.0-litre (1,991cc) M274 aluminium engine - producing 211hp at 5,500rpm and 350Nm of torque from 1,200 to 4,000rpm.
It also comes in two other trims, namely with an upgraded AMG interior priced at RM294,888 and an all-AMG trim at RM299,888.
The lithium-ion battery is under the boot's floor board, and this reduces the 475-litre boot to 335 litres - rear storage space is expandable to 1,370 litres with the seats folded down.
With an electric motor to generate 80hp and 340Nm, the car's combined output is an adrenalin-inducing 279hp and 600Nm.
The C 350 e accelerates from zero to 100kph in 5.9 seconds.
The charging socket is located at the rear-right of the car's bumper.
The lithium-ion battery can be fully charged from 10 percent to 100 percent in about one hour and 45 minutes with the 230V 16A 3.7kW single-phase wallbox (RM7,000) or about two hours with a 230V 13A 3.0kW wall socket.
This brings us to the starting point of our day trip, as the cars were charged in the morning in the basement car park of Wisma Mercedes-Benz before we moved out.
While drivers were supposed to use the pre-set route on the car's navigation system, there was a system bug with our unit and we opted to use Waze and Google Maps on our smartphones instead.
It did not make much difference as the trip was done mainly via the North-South Expressway, and Seremban-Port Dickson Highway.
Five cars with two occupants each started the trip, but only four cars completed the journey as one car's front wheel was deemed too badly damaged after hitting a pothole in Bandar Kinrara.
The cars were shod with 19-inch wheels wrapped with ContiSportContact 5 SSR run-flat tyres sized 225/40 (front) and 245/35 (rear).
It should be noted that this writer and a drive partner had a combined weight of around 140kg, and we agreed to switch off the air-conditioning for the trip.
The prize of two Mercedes-Benz watches awaited the winners of the fuel economy challenge.
Luckily it was not a sweltering day, but being cooped up in an enclosed and sunlit space without air-conditioning for more than an hour still left us wet with sweat by the time we reached Avillion Port Dickson.
The C 350 e has four operating modes namely, Charge (uses combustion engine to help recharge battery while driving), E-save (uses combustion engine when driving), E-mode (uses electric motor when driving), and Hybrid (uses combustion and electric motor when driving).
To conserve fuel, there was no driver change on the way and E-mode was used as much as possible, and Hybrid mode when battery charge is low.
Transmission mode was kept in Economy.
The C 350 e has lots of goodies including a sunroof, comfort-oriented Airmatic air suspension, 360-degree view camera system, active parking assist, keyless entry and a tri-zone Thermotronic automatic climate controls with pre-conditioning.
Still, it was the 13-speaker 590-Watt Burmester surround sound system we really enjoyed, with its high quality audio playback, as we slowly made our way to Avillion Port Dickson.
We were the first to arrive, and based on in-car instrumentation, we finished the 90km journey in in one hour and 23 minutes, at an average speed of 65kph.
Out of the 90km traveled, 48km were on electric-only mode with the combustion engine turned off.
Our fuel usage was recorded by the trip computer as 4.2 litres per 100km.
And we won!
This was despite another car beating us with fuel usage recorded at 4.1 litres per 100km, as earlier arrivals get extra points.
While cars with the air-conditioning turned off, like ours, definitely consumed less petrol, the C 350 e still proved to be a fuel sipper as one car which used the air-conditioning reported fuel usage of 4.5 litres per 100km.
For us, an impressive part of the hybrid technology here was the seamless switch between all-electric mode and starting up the combustion engine - there were no roughness or unpleasant jerks.
The entire journey was conducted in a refined, smooth manner befitting the advanced hybrid technology and luxury status of a Mercedes-Benz plug-in hybrid.