Where the all-electric BMW is funky and feels entirely different to anything else ever offered by the German company, the Mercedes-Benz C350e is stately, posh and feels very much like an ordinary C-Class to drive - classy, superbly built and lively.
While the BMW has a small 650 cc twin-cylinder engine that merely drives a generator to charge the car's batteries and extend its limited 125 km range by a further 100km or so, the Mercedes is a petrol / electric hybrid with a two-litre 155 kW / 350 Nm petrol four-cylinder turbo engine that provides most of the oomph while the electric motor chips in another 60 kW / 340 Nm to help at times.
What the two cars do have in common is that they can both be plugged into an electricity supply point to charge the car at night or whenever it needs to be done.
The i3 takes about six to eight hours for a full charge from a domestic supply, or a couple of hours at a dedicated charging station, while the Merc, with its shorter range, gets the job done in under two hours at a charge station that you can have installed at your home and / or place of business, and somewhat longer from a standard wall plug.
Mercedes boldly claims a combined fuel consumption figure of 2.1-lires /100 km for the C350e, but the reality is that you're unlikely to ever see anything remotely like that in normal driving.
Yes, it normally silently sets sail on electricity, and can even travel up to a claimed 31 kilometres on battery power alone, and for short, slow hops around town you'll perhaps be able to achieve that figure with frequent battery charges, but for anything longer or faster the battery soon discharges, and from then on you'll need a fair bit more petrol.
There are lots of handy techniques to manage the energy recuperation for instance, accelerating and braking, and by planning your trips and choosing a drive mode to conserve battery power for use in the city, but over a couple of hundred kilometres I averaged around 10-litres /100km.
For a fairly large executive car with a 250 km/h top speed that can reach 100 km/h in under six seconds that's still impressive, but I'm not sure the car's worth the asking price of R804 900 when you could buy a less complicated petrol or diesel engine model for a couple of hundred thousand rand less.
You wouldn't use a whole lot more fuel in the real world we all live in, and there would be no unexpected surprises from Eskom at the end of the month. And the boot, unencumbered by battery storage needs, would be considerably larger.