Drawing on weight-saving construction methods first explored in the development of BMW’s i models, it incorporates a number of load-bearing carbonfibre-reinforced plastic elements in what represents a first for the company’s more traditional models.
The lightweight material is used within the header rails, sills, B-pillar, centre tunnel and C-pillar in a move that, in combination with additional aluminium elements, is claimed to bring a 40kg reduction in weight over the structure used by its predecessor.
Further savings have been achieved with changes to the outer bodyshell, which receives newly designed aluminium doors (claimed to weigh 12kg less than those used by the fifth-generation 7 Series) as well as an aluminium roof panel for the first time.
All up, the new flagship BMW saloon is said to tip the scales 130kg under that of the old model in 740iL guise, as driven here. If this holds true, the new model should arrive with an official kerb weight figure of 1715kg, making it just 40kg heavier than the existing 535i.
As a point of reference, the four-wheel-drive Audi A8 3.0 TFSI weighs 1830kg, while the rear-wheel-drive Mercedes-Benz S400 Hybrid comes in at 1850kg.
Because the car is not planned to be unveiled until the Frankfurt motor show in September, BMW is holding back on many other details, including its dimensions. Visually, the long-wheelbase prototype appears close to the outgoing model, which measures 5220mm in length, 1900mm in width and 1480mm in height.
The 740iL is the first BMW model to receive the company’s new 3.0-litre in-line six-cylinder petrol engine. The new unit, known internally as B58, shares its architecture with the smaller three- and four-cylinder engines unveiled recently in other BMW models, with the block, cylinder head and oil sump made of aluminium.
Improvements in the operation of the twin-scroll turbocharger, valvetronic fully variable valve control and double vanos variable camshaft control are claimed to bring enhanced low-end response, added mid-range tractability and subtle increases in output.
Nothing is set in stone at this stage, although officials suggest the new engine will improve on the 316bhp and 332lb ft of its predecessor, the N55. As before, the driver can choose between a range of differing driving modes, including Eco Pro, Comfort, Sport and Sport Plus.
The new engine is mated to a revised version of BMW’s eight-speed automatic gearbox featuring all the latest fuel-saving technology, including automatic engine stop-start, brake energy recuperation and a new coasting function that idles the engine on a trailing throttle.
Standard 7 Series models continue with rear-wheel drive, although there are plans to extend the number of four-wheel-drive models this time around, according to BMW’s newly installed development boss, Klaus Froehlich.
Although BMW intends to make available a new key fob with an optional digital display, it was kept hidden as we prepared to drive the new 7 Series. Getting comfortable is easy, your efforts to tailor the perfect driving position enhanced by a wide range of seat and steering wheel adjustment. Newly designed seats provide good support, despite their reasonably soft cushioning.