What is it like to drive?
The M50 is seriously rapid. It bolts off from a standstill. It blasts ahead when an outside-lane blockage clears. It's a warp module for A-road single-carriageway overtaking. Lots of cars are rapid-accelerating after they've spooled up, but in a quick EV the spool-up time is zero. You need to look a long way down the road, or you'll be there before you know it.
A setting called 'sport boost' unleashes all the power (not just a quicker accelerator map) and increases the volume of the sound synthesis. Which is a 'composition' from film-score mogul Hans Zimmer.
In normal traffic you'll be happier driving the i4 in one of its milder modes, wherein it's smooth and easy to dawdle.
Because it's AWD, the M50 can use huge regeneration – up to minus 265bhp – and still keep a workable front-rear brake balance. You can opt to get that regen from lifting off the accelerator. But this gives the right pedal too much to do, controlling all that positive and negative longitudinal g.
So Top Gear turns off one-pedal driving and uses the actual brake pedal to do the braking. Crazy unconventional us. It's no less efficient: the brake pedal invokes the discs only when it's beyond the point of maximum regeneration. Unfortunately, the pedal is too sharp, unprogressive and short on feel.
Not much feel bubbles up from the steering wheel either. It has an accurate but glutinous action. Adding a false weight via the sport menus is no help. But it can sure summon immense cornering force. Not much happens to the attitude of the accelerator mid-way. The front-rear torque-vectoring and a traction control system act blindingly fast and smoothly, but at road speed they don't exactly play it for laughs.
The M50 has self-levelling air suspension for the back wheels, and adaptive dampers. The whole system is well programmed for a sporty but tolerable ride, easing off the sharp edges of small pot-holes and ridges.
As it goes fast, so it charges fast. It'll accept 200kW at peak. So on one of the 350kW stations sprouting across Britain you have the potential of picking up another 100 miles in 10 minutes in the i4 40, and 87 in the M50. Or half an hour from 10-80 per cent. The battery is 80.7kWh net. At a 50kW station, 10-80 per cent should be just over an hour.
The i4 gets all of BMW's latest driver assist gadgetry. It works well, but is sometimes too keen. For example on a twisty single-carriageway the lane assist (which defaults on when you start the car as they all must by law these days) knocks you away from the smooth line. And it's a distracting pain to switch off, as we'll see in the interior section.