Regardless of whether you choose the fully electric i3 or the range-extender version, the rear wheels are driven by the same electric motor. It has 168bhp, which is enough to take the i3 to a maximum speed of 93mph – so it's easy enough to keep up with motorway traffic. Perhaps more notably, though, the i3 feels extremely nippy around town; you'll find it hard to resist embarrassing conventional petrol and diesel cars away from traffic lights.
The range-extender's petrol engine is there solely to stop the battery from going flat; it's not connected to the wheels and you don't get any additional performance from it. In fact, because of the increased weight, the range-extender i3 is slightly slower than the pure electric i3.
The i3 has three driving modes. 'Comfort', oddly enough, gives you maximum performance, while 'Eco Pro' increases the aggression of the energy recuperation when you lift off the accelerator and limits the top speed to 70mph unless you floor the accelerator to over-ride it. There's also 'Eco Pro+', which is really suited only to urban use because it limits the top speed to just 56mph.
BMW i3 ride comfort
The engineering brief for the BMW i3 was clearly to stop this fairly tall and narrow car from swaying about through bends, so the suspension is decidedly firm.
Even on the standard 19in wheels, you'll notice plenty of thunks and bumps along pockmarked urban roads – which is a shame, given that the car is primarily designed to be used in cities. The ride on the optional 20in items is, unsurprisingly, even harsher and crosses the line into uncomfortable.
BMW i3 handling
Although it's an electric car, the i3 is still a BMW at heart, and the company's engineers have managed to make it feel surprisingly responsive and agile for something that's mostly designed for around-town use.
The steering has a consistent, satisfying weight to it, and a tiny turning circle helps make the i3 ideal for the urban fray. You'll be amazed at its manoeuvrability in tight spaces; it's perfectly suited to slipping into tight parking spots.
At faster speeds, the i3 can feel a bit twitchy and nervous, though, so it isn't as fun to drive along a twisting country road as you might imagine. Overly quick yet uncommunicative steering can also force you to take multiple bites at corners, and despite the fact that the car's relatively skinny tyres produce more grip than you might expect, sudden bumps can easily knock the i3 off-line.
BMW i3 refinement
The i3's electric motor is impressively refined; there's none of the high-pitched whine that you get in, say, the Nissan Leaf. In fact, that hushed nature means you can hear more road noise, which the i3's carbonfibre construction struggles to suppress; there's a mixture of rumble and resonance that can become tiring – especially on longer motorway runs.
The range-extender version does have a rumble when the two-cylinder petrol engine kicks in – a bit like someone starting a lawnmower in a distant garden – but you'll notice it only when you slow down for junctions. At anything beyond 50mph you won't even know the petrol engine is running.
Braking performance is perfectly adequate, but you'll soon learn to drive with a 'single-pedal' technique around town, anticipating when you're going to have to come to a halt and allowing the car's energy recuperation systems to slow you down to a stop naturally. It sounds odd, but it soon becomes second nature, particularly since it maximises the i3's range.
The electric-only i3 is cheaper and lighter than the range-extender version, so it's a little quicker when accelerating and has a few more miles of electric-only range. It's worth noting, though, that despite the lack of an engine sitting alongside the electric motor in the back, you don't get any more boot space. It's the best value i3 in the range for private buyers or company car users, so it’s our favourite version.
If you're still suffering from a bit of range anxiety – or if your i3 is going to be a bold choice as your only car – then the range-extender version could appeal. Its nine-litre fuel tank and small petrol engine add about 80 miles to the range, and give you the scope to keep on motoring without the need for a lengthy recharge.