BMW is well and truly in the realm of electrified vehicles, with the likes of the i3 and the mid-engined i8; it also currently has the iX3 in development that’s due to debut this year. Its bread and butter model, the 3 Series has included a plug-in hybrid in its ranks, though without a fully electric version – until now.

Here, our spy photographers have spotted a G20 development unit with ‘Electric Test Vehicle’ stickers along its sides. The front end of the electric 3 Series bears the most exterior visual changes, where the kidney grille here is closed off to improve airflow efficiency as the EV powertrain dispenses with the cooling needs of internal combustion engines.

Further downwards, the front bumper is also concealed, though the centre section appears to take after that of the G20 330e, and the outboard sections also hint at similar shapes as applied to those on the plug-in G20. Viewed in profile, the electric mule here appears to be G20 business as usual, though rolling stock on the eventual production car will feature unique items.

Around to the back, the electric 3 Series wears a unique rear bumper as there is no need for exhaust outlets and its cutouts, while the rest of the G20 sedan’s exterior bodywork appears unchanged. If the proportions appear slightly unusual, that’s because this is likely a long-wheelbase version of the G20 3 Series, which historically means that the use of this particular chassis could turn out to mean a China-specific model.

The stretched body also means there will be additional room for larger battery packs and therefore greater charge capacity, which could then mean the introduction of a longer 3 Series chassis for the rest of the world. The iX3 crossover will be BMW’s first to adopt its fifth-generation eDrive technology, which helps the motor in the iX3 deliver 286 hp and 400 Nm of torque; outputs which are close to the 330e’s 252 hp and 420 Nm.

Should this electric powertrain be used for the EV 3 Series, its outputs will almost match those of its PHEV and pure petrol siblings. Depending on the battery pack’s capacity, the EV 3 Series could feature a range that matches – or at least comes close to – the iX3’s estimated range of over 400 km.