The next-generation BMWM5 will be revealed this August with a variable all-wheel drive system and an uprated V8 engine producing around 600bhp, making it the most technically advanced car to wear an M badge yet.
In the run-up to its public debut at the Frankfurt motor show, the car is undergoing high-speed testing at the Nürburgring, where it has been spotted this week wearing new design features including larger front air intakes to supply its twin-turbocharged 4.4-litre V8 petrol engine with more air.
Despite being based on the current car's unit, power for the 2018 5 Series flagship (which has been imagined without covers by Autocar in the picture below) will be substantially increased from the old model's 552bhp, overtaking the limited-run 592bhp M5 Competition Package as the most potent M5 yet and aligning the car closely with its archrival, the latest Mercedes-AMG E 63, which has 603bhp in its fastest guise.
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The car will use a specially developed version of BMW's xDrive all-wheel drive system - the first time one has been used on an M5 - that uses a multiplate wet clutch located in the gearbox on the output to the front driveshaft. It provides a continuously variable split between front and rear axles to enable advanced torque vectoring.
This will improve agility and performance, but also enable more fuel efficient running in less aggressive engine modes. In total, the car will have up to five driving modes, including an M Dynamic setting where 100% of torque will be sent to the rear wheels, accessed through buttons mounted on the steering wheel.
This widened flexibility for the car's drive systems will be enhanced with the fitment of an eight-speed automatic gearbox in place of the outgoing car's seven-cog system. The new torque-converter 'box will be based around the standard ZF-produced gearbox used in other 5 Series models.
This long list of technical upgrades will make the new M5 the fastest accelerating and most dynamically capable M5 yet, with the old car's 4.3sec 0-62mph time due to be beaten by close to a second thanks to the new car's improved traction and peak outputs. Top speed will again be restricted to 155mph, although an optional M Driver’s Package will enable buyers to raise it to 190mph with new engine management software and the fitment of Z-rated tyres.
BMW senior vice-president Hildegard Wortmann told Autocar earlier this year that the model will make as significant a step forward from its predecessor as the latest 7 Series has, both in terms of performance and technology.
Details of the new M5’s chassis set-up remain under wraps. However, engineers involved in its development say it adopts a largely bespoke double wishbone (front) and multi-link (rear) suspension system, together with new electro-mechanical steering that includes the active rear-steer function available on selected 5 Series models. Its body structure was leaked onto the internet in CAD drawings last year.
Along with the rest of the 5 Series range, the next M5 will feature an evolved exterior design that takes influence from the Pininfarina Gran Lusso Coupé concept of 2013. Photographed development cars confirm it’ll get a more heavily raked rear window and a sloping boot deck, giving it a sleeker profile and more shapely rear end than the current model.
Inside, much of the car’s dash design will resemble that of the new 7 Series, and it'll also get 48-volt electrical architecture to enable advanced autonomous driving systems. A self-steering mode will operate up to a pre-determined speed, and a sophisticated anti-collision system and fully autonomous braking will also be available.
In-car technology will come from BMW’s fifth-generation iDrive system, as used by the 7 Series. It supports new touchpad and touchscreen functions, allowing passengers to operate features in a similar style to that of a smartphone, with familiar pinch, point and swipe commands, or alternatively via an updated rotary dial mounted on the car’s broad centre console.
Following its reveal and public debut, the car will go on sale at the start of 2018. Insiders have said the tech-heavy model will be priced higher than the outgoing model, so a starting figure approaching £80,000 is possible.