BMW i3 prototype review: the 463bhp all-electric 3 Series is coming…

Hang on, that’s not an i3?

Ah, well it is, but not as we know it. The previous i3 was BMW’s clever little city car launched back in 2013, but despite its futuristic carbon construction and Scandi-cool interior, it only lasted a single generation. It was discontinued in 2022 just a few days after the 250,000th example had been screwed together. Sad times.

Still, while this new i3 is a much more traditional three-box saloon in shape, it is pretty advanced in other ways.

Hang on, is it related to that new iX3?

You mean the reigning TopGear Car of the Year? It certainly is. The new i3 is the second model in BMW’s Neue Klasse family, which means it’s pretty much a complete reset for the 3 Series. Bold.

It’s powered solely by electricity for a start, and one of the major developments that BMW has made for this New Class is the creation of four ‘superbrains’ that power the infotainment, automated driving, in-cabin comfort and vehicle dynamics. We’re told that this allows for 20 times more computing power than the previous generation of BMWs, all while saving 600 metres of cabling.

Of course, being a member of the 3 Series family, it’s the vehicle dynamics brain that’s perhaps the most important here. Rather excruciatingly christened the ‘Heart of Joy’, it’s a supremely clever single processor that looks after the electric motors, brakes, steering and stability control. In the past each of those ‘actuators’ would have had its own separate processor, but the Heart of Joy bundles them all together for better communication and 10 times faster response times.

BMW is rather proud of it having developed all of the software in-house, and it’ll likely underpin pretty much every new model in its foreseeable future.

It’s clearly camouflaged, but what else do we know about the i3 so far?

We’ll see the final design later this month, but take a look at the Vision Neue Klasse concept from late 2023 and you’ll get an idea of what BMW’s aiming for. The dimensions are roughly the same as the current G20 3 Series, but the wheelbase is longer and the overhangs shorter – particularly at the rear. Up front you’ve got a nod to a shark-nose and kidneys that reach out to engulf the headlights.

Full facts and figures will then be revealed later in the year, but we do know that it’ll mirror the iX3 in featuring just one powertrain option at launch. That’ll be the i3 50 xDrive, with twin motors, all-wheel drive and a hefty total of 463bhp. It also shares the iX3’s 109kWh battery, but thanks to the more slippery shape it should be able to claim even more than that car’s 500 miles of WLTP range.

Looks pretty chilly where you are…

Yep, we packed our TG-branded bobble hats and headed off to BMW’s winter testing facility in Arjeplog for a go in some 95 per cent complete pre-production prototypes, because it turns out the first all-electric BMW 3 Series is quite a big deal.

Come on then, is it any good?

As you can see, we’ve only driven on frozen lakes and snow-covered roads so far, but first impressions of the i3 are really rather impressive.

This is a two-tonne, all-wheel drive electric saloon, but it seems to mask its weight well and feels properly dynamic. Even on very low grip surfaces there’s a pleasing amount of feel from the steering to let you know what the front tyres are up to. Sport mode adds a little extra heft but it’s not excessive, and it also means more of the 476lb ft of torque is sent rearwards to help the 50 xDrive feel that little more agile.

No word on a 0-62mph time yet, but the twin motors provide plenty of shove and – so far at least – it seems to be a very natural, smooth car in which to make swift progress. Every inch the sporty German saloon, then.

How does this Heart of Joy help?

It’s slowing and stopping where the new vehicle dynamics brain has possibly the greatest effect. BMW reckons around 95 per cent of braking is now done by electric motor regen rather than pad on disc friction, but because both of those are now controlled by the same processor with lightning-fast reactions, the pedal feel is always firm and true. Yep, even when you stamp on it and activate the ABS.

And because that brain is also responsible for the stability and traction control systems, plus the steering assistance, an ABS stop on ice from 60mph creates very little fuss indeed. Don’t try this at home (unless you've got a winter testing facility in your backyard), but you can even take your hands off the wheel.

Stopping more sedately is equally impressive, with the same ‘soft stop’ function as seen in the iX3. That’s essentially the car using regen to come to a complete halt with no jerkiness or brake noise at all. Feels very much like witchcraft.

The Heart of Joy also has the capability to control rear-wheel steering, active anti-roll bars and adaptive suspension setups, but the i3 requires none of those and seems to benefit from a little bit of simplicity.

What’s the ride like?

Interestingly BMW has gone for a completely passive spring and damper setup here. Body roll is kept to a minimum through bends and while the ride seems to be on the firmer side, it certainly wasn’t uncomfortable on the rougher sections of road we experienced. It’s also remarkably quiet inside once you’ve turned off the synthetic sound.

Looks like it’ll do big skids…

Ah yes, that’ll be the Dynamic Traction Control. Stick the i3 into this mode on a frozen lake, boot the throttle and watch it behave like a proper rear-wheel drive sports saloon as the tail kicks out and the computers hold the slide.

It’s properly impressive, with the Heart of Joy using regen to smoothly keep the car balanced while not totally robbing the driver of power or snatching at the brakes. It uses similar tricks to combat understeer, too.

Oh, and ‘DSC off’ really does mean off. Don’t ask us how we know this, but could someone pass a sick bag?

Did you get a proper look at the inside?

In a word, no. Of course, it’s fairly tricky to miss BMW’s new Panoramic iDrive system with its giant display running right across the bottom of the windscreen. Much like in the iX3, that replaces your traditional instrument binnacle, and then there’s a slanted central touchscreen that seems to be customisable with different widgets and shortcuts.  

The rest of the interior was kept firmly under wraps, although we did get on well with the new steering wheel (and its thumb rests). Shame there are no paddles for adjusting the level of regen, though.

A quick sit in the rear proved that while leg and head room is okay, you won’t be able to get your feet under the seat in front, so taller folk will have their knees up beside their ears.

Anything else you can tell us about it?

Remember when we said it was powered solely by electricity? Well, those badged i3 will be, but much like with the iX3 there'll also be petrol and hybrid versions available. Expect those to get the Neue Klasse look, but with much of the tech and powertrains from the current 3 Series.

Oh, and let us not forget the M division. We already know that the next M3 will be offered in both petrol and electric forms, with the latter deploying quad motors for a rumoured total of over 1,000bhp. There’s even been talk of simulated gearshifts a la Hyundai Ioniq 5 N. Someone fetch a pacemaker, that Heart of Joy is going to have a lot of work to do…