BMW is preparing an unusual engineering feat with its most important sedan. The next-generation 3 Series and the fully electric i3 will look remarkably similar to one another, yet underneath the shared bodywork they are fundamentally different cars, built on separate platforms and assembled in different factories.
The combustion-powered model, codenamed G50, continues on BMW's tried-and-tested CLAR architecture, which was engineered to accommodate petrol engines and plug-in hybrid systems. The electric i3, known internally as NA0, rides on the EV-only Neue Klasse platform. The two cars are not even produced at the same site: the i3 is built in Munich, while the next 3 Series will be manufactured in Dingolfing.
BMW design chief Adrian van Hooydonk has said customers would be hard-pressed to tell which car is electric and which has a combustion engine. Prototypes spotted so far support that claim, with the i3 effectively previewing the next-generation 3 Series design, including minimalist surfacing, a new interpretation of the kidney grille and slim lighting elements.
The most telling difference lies at the front. Because the i3 was designed from the outset as an electric vehicle, engineers did not have to find room for an internal-combustion engine in the nose. Instead, it offers a front trunk with 31 litres of capacity where the G50 houses an engine. The Neue Klasse architecture also gives BMW far greater freedom in packaging, allowing the wheels to be pushed closer to the corners and the front overhang to be shortened.
The combustion 3 Series cannot match that flexibility. The G50's CLAR bones must accommodate engines and plug-in hybrid hardware, so the front section has to be longer. That matters because BMW is not abandoning six-cylinder engines. The recently revealed M350 xDrive uses the most powerful version of the B58 engine yet, and packaging such a unit in the same nose as the electric i3 is simply not possible. As a result, the G50 has subtly different proportions, with more sheet metal ahead of the front axle, while the i3 has a shorter nose. The difference is dictated by engineering rather than styling.
The contrast should be even clearer inside, particularly in the rear. The Neue Klasse platform was created exclusively around electric propulsion, allowing a completely flat floor. Electric motors and their associated hardware do not require the transmission tunnel found in a combustion BMW. The 3 Series must still work around the compromises inherent in CLAR, including a mechanical connection between engine and driven wheels, an exhaust system and other components that an EV does not need.
Despite those mechanical divisions, BMW has deliberately given the two cars a shared visual identity. The cabin follows the same philosophy, with the G50 receiving a Neue Klasse-style dashboard including iDrive X and Panoramic Vision. A recent look inside a 3 Series prototype confirmed how closely the interior will follow the electric i3. Rather than forcing the electric version to look dramatically different, as Mercedes did in the past, BMW has created a design language that can adapt to two fundamentally different architectures.
The strategy extends to the estate body style. Once the Touring models arrive, the combustion and electric versions should look as though they were cut from the same cloth, even though they are not. So far only the i3 Touring, codenamed NA1, has been confirmed, though a 3 Series Touring with four- and six-cylinder engines is expected.
BMW has taken a different path before. The previous i3 Sedan was a long-wheelbase 3 Series built and sold in China, using an electric conversion of the CLAR platform. It still looked as though it had a combustion engine under the bonnet, even though it did not. The new approach unifies the design while separating the engineering. The new i3 Sedan has already been revealed, and the next-generation 3 Series is expected to appear without camouflage by the end of the month.