BMW developing lightweight 7-series

Testing of the new BMW 7-series is at an advanced stage ahead of the car’s debut at the Frankfurt motor show in September 2015 before going on sale internationally, in 2016.

Key among the goals for the new 7-series is a significant weight reduction via the use of a combination of aluminium, magnesium, high-strength steel and carbonfibre-reinforced plastic (CFRP), the latter of which is set to be used not only for the bonnet and roof but also in load-bearing areas in the floorpan and body. BMW boss Norbert Reithofer said, “It will set a new standard in its class in terms of weight saving.”

Engineers say processes developed for the i3 and i8 hybrid cars have been adopted on the new BMW flagship in a bid to shed up to 200kg over the current generation car. This should ensure that the successor to the lightest of today’s 7-series models, the 740i, tips the scales at around 1650kg, or less than the existing 535i.

As is with the current car in the international markets, the luxury sedan will be built in standard and long-wheelbase guises, but plans also exist for an extra-long-wheelbase model. Underpinning the new car is a modular platform that forms part of a longitudinal engine matrix that is already used by the 3 and 4-series and is set to be adopted by replacements for the 5 and 6-series. The light but rigid structure is allied to an aluminium-intensive suspension system that uses double wishbones up front and a multi-link rear set-up at the rear together with a new generation of air springs and road-scanning technology. That's in combination with stereo cameras, with the package aimed at giving the new BMW greater levels of ride comfort and better refinement than before.

The new model will be offered with a range of turbocharged four, six, eight and 12-cylinder petrol and diesel engines, a standard nine-speed automatic transmission and the option of rear or four-wheel drive. The petrol engines are based around a new modular architecture with a 500cc individual cylinder capacity. A heavily updated version of today’s 3.0-litre, in-line six-cylinder engine is planned, along with a new 4.0-litre V8 and a 6.0-litre V12, the latter two set for use by Rolls-Royce. Diesels will include a 2.0-litre four in a new entry-level model and 3.0-litre in-line six, the latter of which will appear in three states of tune and both twin and triple-turbocharged forms.

To further boost the model’s presence in the luxury performance market, BMW is looking at creating a new M7 or M750i M Performance version, likely to receive a heavily tuned version of the M5’s twin-turbo 4.4-litre V8 producing more than 600bhp. Also planned from the off is a plug-in petrol-electric hybrid, the exact make-up of which is still to be decided.

The Future Luxury concept seen at the Beijing show this year provided the first hints not only of BMW’s new design language but also its in-car technology, which will rely heavily on speech recognition in a move aimed at reducing the number of controls and lessen dependency on the rotary iDrive controller.

Among the key rivals for BMW's 7-series will be the new Audi A8, which has also been spotted testing on international roads.