Engine options, top speed, acceleration and refinement

Because only the BMW i3’s electric motor is connected to its (rear) driven wheels, this city car has the kind of power delivery that we’ve come to know and love from a pure EV. With peak torque from zero revs and no discernible lag at any speed, you put your foot down and the i3 responds immediately. It responds strongly, too.

The 0-62mph sprint is claimed to take 7.3sec in the all-electric model, and is accompanied by a seamless, prolonged shove in the back. The top speed may be only 99mph, but the performance on the way to it wouldn’t shame a warm hatchback. The range extender, which weighs 120kg more, takes a slower 8.1sec and has the same top speed. The i3S with its more powerful motor can do the same sprint in 6.9sec (or 7.7sec in Range Extender form), before topping out at the same top speed of 99mph.

Unlike most plug-in hybrids, the range-extending petrol engine never drives the wheels

Normally, you’d be frightened to use all of that poke in an EV because of the rapidly reduced range that a heavy right foot brings. And on battery power alone, the i3, in our hands, returned a typical range of about 75 miles.

But, in range-extender versions of the i3, the fact that there’s that twin-cylinder bike engine secreted beneath the boot floor gives you a certain confidence, even if the fuel tank is only bike-sized, too.

It’s possible to ask the i3 to hold its battery charge once it has fallen below 75 percent full, from which point the car will run with electrical power provided by the petrol generator.

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In doing so, we found that the battery depletes a little between switch-offs, but we still rate the range extender as an extremely worthy feature, turning the i3 from short-hop urbanite into something acceptable as an only car.

Find yourself without electrical back-up for a few days and the i3 will give you about 40mpg on generator, accompanied by a muted, quite endearing twin-cylinder thrum.

On battery power, we saw as much as a 94-mile range and as little as 68 miles. With a fresh charge and a fresh tank, then, you could expect comfortably over 150 miles before having to find a power source of one kind or another.