BMW has electrified the legendary M5 with a new plug-in hybrid system mated to a petrol V8, giving a total of 717bhp – the most ever.

The M HYBRID system also gives a stonking 1,000 Nm of torque, allowing it to accelerate from 0-62 mph in 3.5 seconds. More importantly for anyone with an extremely generous company car scheme, the new M5 has official emissions of 39 – 37 g/km and an electric-only range of 43 miles, meaning the benefit-in-kind tax is at just 8% for the 2024-25 tax year. That will make it £8,768 cheaper per year than the smaller, petrol-only BMW M3 for a 40% taxpayer.

In all-electric operating mode, the new BMW M5 can also hit speeds of up to 87 mph if you like to collect speeding tickets in silence. The battery ia located low in the car’s underbody to improve weight distribution and has 18.6 kWh of usable energy. It can currently be charged at only 7.4 kW, but from November 2024 production the maximum charging rate will go up to 11 kW.

The 4.4-litre V8 petrol engine integrates with an eight-speed M Steptronic transmission. It develops maximum output of 585 hp and peak torque of 750 Nm. The electric motor delivers a maximum output of 197 hp and a nominal torque of 280 Nm. However, it uses a gearbox to step up the effective torque at the transmission to 450 Nm.

Even in electric mode, BMW have made sure the M5 has the sounds drivers would expect.  The ‘BMW IconicSounds Electric’ system provides responses to movements of the accelerator when the car is operating in all-electric mode and is said to generate an ‘engaging boost track’ to highlight when extra electric power is added to the output of the V8 engine.

The new M5 is available to order now, priced from £110,500. The Touring version is also orderable, although there is no pricing information yet.