2015 BMW 7 Series 740iL prototype first drive

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.

While the interiors of the various prototypes we drove were comprehensively covered with quilted cloth, we could still detect parts of the newly designed dashboard, which seemed to have higher-quality materials than those of the outgoing version, along with a new generation of switchgear.

One feature we did get to try was the new digital instrument display, which is similar in design to that adopted by the 5 Series last year. Depending on the driving mode chosen, it lights up in either a predominantly white, blue or red hue.

Also included is a fifth-generation version of BMW's iDrive system. Significantly reworked, it introduces a new touchscreen display that allows you to operate the various infotainment functions in a similar style to that of your smartphone, with pinch, point and swipe commands. You can also use an updated rotary dial mounted on the new car’s broad centre console to control everything.  

More significant, though, is the appearance of gesture control for the first time. Set to be a high-priced option, it uses a three-dimensional sensor mounted within the rooflining to detect hand movements that are used to control various functions, including the volume of the audio system as well as the acceptance or rejection of phone calls. All up, the new system detects five different gestures, including clamp, point, rotate, swipe and a two finger command.   

The 740iL feels brisk away from the mark; the new engine is terrifically smooth and refined, and the revised gearbox shifts gear quickly and smoothly. There is great flexibility at the lower end of the rev counter and a real eagerness to rev through the mid-range.

BMW has not revealed any official performance figures yet, although the new model is said to improve on the standing start acceleration of its predecessor, which has a 0-62mph time of 5.7sec, thanks in part to its lower kerbweight.

There is a pervading suppleness and quietness to the driving experience. Overall refinement is superb. The sound of the engine, now encapsulated in a sound-deadening jacket, rarely intrudes into the cabin. The rustle of wind around the redesigned exterior mirrors is only faintly perceptible at three-figure speeds. The only real weakness is the amount of road noise being channelled back through the chassis.

Underpinning the new 7 Series is a newly developed double-wishbone (front) and multi-link (rear) suspension system featuring air springs both front and rear, instead of just at the rear as on the old model. In a move aimed at enhancing rolling comfort, the new set-up comes with continuously varying damping as well as an automatic self-leveling function as standard.

Also included is an upgraded version of BMW’s Dynamic Drive roll-reduction system featuring electro-mechanical actuation of the roll bars in place of the older hydraulic actuation, leading to what BMW chassis ace, Jos van As, describes as faster stabilisation of the body during cornering.

“We haven’t dialled out the roll angle completely as some rivals do, because we feel the driver needs a point of reference to the amount of lateral acceleration the car is experiencing in corners. But the roll bars now react faster, meaning there is a more progressive increase in lean,” he says.

Reflecting a clear shift in philosophy with the tuning of the suspension, the new 7 Series offers the driver the choice of four differing modes via the so-called Driver Experience Control function. They include a new Comfort Plus mode, demonstrating BMW's efforts to instill the new car with a more cosseting feel than its stiffly sprung predecessor. The driver can also call up Comfort, Sport and Adaptive modes – the latter of which is also new.

In an effort to ensure its new range-topping model retains its long-held reputation for handling leadership in the luxury saloon ranks, BMW has also worked hard at reducing unsprung mass. Included on the 7 Series is a series of new aluminium chassis components, including the wheel carriers, brake caliper housings, brake disc carriers and rear transverse suspension arms.

As mentioned, some 40kg has been saved, bringing a 10kg reduction in unsprung weight at each corner. As before, BMW also claims a perfect 50:50 front-to-rear weight distribution, while the efforts to trim weight within the roof have also resulted in the crucial centre of gravity being lowered slightly.

Allied to the new suspension is a new electro-mechanical steering system. It reverts to a fixed-ratio rack in place of the variable-ratio rack of the old model. The new model also uses a rear-wheel-steer function that provides up to three degrees of counter steer for added maneuverability around town, or alternatively two degrees of parallel steer for greater agility out on the open road.      

Driven around varying roads at BMW’s Miramas test track in France this week, the new 740iL immediately felt more fluid and engaging than the model it replaces when operating in Sport mode. While the steering is lighter than before, it operates with greater precision and greater consistency off centre.