To that end, it is set to largely retain the current car’s turbo-only four- and six-cylinder petrol and diesel motors, as well as an expanded choice of plug-in hybrid systems centred on a 2.0-litre or 3.0-litre petrol combustion unit.
Less certain is the survival of the 4.4-litre V8-powered M550i xDrive, which arrived in the UK in 2020 – after two years on sale elsewhere – to occupy the gap between the 540i and top-rung BMW M5. Its twin-turbo N63 petrol engine dates back to the first-generation BMW X6, launched in 2008. This will make the unit 15 years old when the Mk8 5 Series arrives, so it will not be a strong candidate for expensive modifications to be made compliant with new Euro 7 emissions regulations.
One possibility for the M550i’s successor is an uprated version of the 545e PHEV’s four-wheel-drive powertrain, which comprises a 3.0-litre straight six and a 107bhp gearbox-mounted electric motor for a combined 388bhp and 442lb ft.
BMW has previously said CLAR-based PHEVs could accommodate electric motors with up to 201bhp, which hints at the potential for a circa-500bhp hybrid to sit beneath the M5. The M5 itself has been widely tipped to match its arch-rival, the Mercedes-AMG E63, in adopting plug-in power for its next iteration but with a petrol unit of larger capacity than AMG’s electrified turbo four.
BMW development boss Klaus Fröhlich has previously said there will not be any fully electric M cars until 2025. “Until then, we will have normally aspirated, turbo and ‘powered’ PHEV applications that deliver what we want to achieve,” he said, suggesting pure-electric powertrains and platforms remain too heavy to match the dynamic performance of today’s M cars.
