13/8/12

Overview: BMW 7-series

Less than three years after the introduction of the current, fifth generation of 7-series, the new model represents an evolution of the line and an opportunity to deploy some of the off-the-shelf electronic and electrical systems that are growing seemingly exponentially in their scope and capabilities. In fact, so cheap are these systems becoming that it’s getting hard for premium manufacturers to stay ahead of the mainstream in the driver-assistance and ‘infotainment’ features they can offer.

New features for the Sebener include (optional) LED headlights, a multi-functional, customisable ‘virtual’ instrument display, some new and uprated engines — BMW’s formidable 381PS turbodiesel is now available — and the universal fitment of ZF’s 8HP eight-speed automatic transmission. Also noteworthy are the standard self-levelling air suspension at the rear and an Eco Pro driving mode — though we wonder how much use the latter will get in a car of this size.

BMW 7-series, standard wheelbase (top) and long wheelbase (above).

Powertrain and chassis

We have mentioned already that all variants of the new 7-series use ZF’s eight-speed automatic. Three engine variants — 730d, 740d and 750i — are available with four-wheel drive — BMW calls this X-Drive. The 750d, whose 740Nm torque output is considered a little too ample for rear-wheel drive, is available only with X-Drive.

So far as engines are concerned, the choice is wide — four petrol engines, three diesels and a petrol-electric ‘mild’ hydrid; this last, the second-generation Active Hybrid 7, uses a variant of the same transmission as the other cars.

Alongside the flagship 760i, with its six-litre V12, there is a choice of the BMW 740i with a new six-cylinder in-line petrol engine, or the BMW 750i, with a revised V8. All of these engines are turbocharged. Additionaly, a 730i model, with an atmospheric three-litre straight six, is available on some markets.

All three diesel engines are based on the same structure and all have the same 2993cc swept volume. In their fuelling and intake systems they vary widely, though, with either one, two or three turbochargers and fuel injection at 1800 bar, 2000 bar or 2200 bar (180MPa, 200MPa or 220MPa).

The second-generation BMW ActiveHybrid 7 combines a new turbocharged six-cylinder in-line petrol engine with a 55PS electric motor.

The range-topping 760i is a fine exercise in overkill. The six-litre V12 has two turbochargers, Double-Vanos valve control and direct fuelling, The all-aluminium powerplant generates 544PS and 750Nm, the latter from 1500rpm. It is predictably thirsty, with NEDC rolling-road fuel economy (if that’s the right word) of 22.1 mpg and CO2 emissions of 299g/km. Despite the torque output, this model is available with rear-wheel drive.

Making its début under the bonnet of the 750i is a revised V8 with two turbochargers, Valvetronic, Double-Vanos and direct injection. The 4395cc unit’s fuel injection has been updated and charge cycle losses have been reduced, thanks in the main to the infinitely variable control of intake valve lift. Thus performance and economy have improved. In its latest form, the engine generates 450PS — up 10 per cent. — and 650Nm (an increase of 8.5 per cent.); the torque peak is maintained between 2000rpm and 4500rpm. Overall fuel consumption is 8.6l/100km or 32.9 mpg; CO2 emissions come out at 199g/km. The economy figure represents a 25 per cent. improvement over the previous model. (Oddly, in the Chinese market the BMW 750i is powered by a four-litre variant of the engine, with 408PS and 600Nm.)

The 740i receives a new three-litre straight-six. Directly fuelled, it uses a twin-scroll turbocharger, Double-Vanos control of valve lift and Valvetronic camshaft timing. Maximum outputs are 320PS and 450Nm, the latter from a creditable 1300rpm. Overall fuel consumption of 7.9l/100km or 35.8mpg produces a CO2 yield of 184g/km. These figures represent a 21 per cent. improvement over the previous 740i.

The three-litre power unit of the entry-level 730i has not changed. Headline outputs are 258PS and 310Nm. Driving through the eight-speed transmission allows a fuel saving of 13 per cent. at 8.6l/100km or 32.9 mpg; CO2 emissions are 199g/km. While we do not place much faith in the NEDC rolling-road fuel economy figures, it’s worth noting that the 730i is markedly thirstier than the 740i.

The 750d is avaliable only as an X-Drive model, with permanent, electronically controlled all-wheel drive. Its engine is the most muscular of the three 2993cc diesels used in the 7-series, deploying three-stage turbocharging with variable turbine geometry. The first blower starts work at just above idle; at 1500rpm a larger, high-pressure turbo starts working; and a third comes in at 2700rpm. Piezo-electric fuel injectors are used, with an injection pressure of 220MPa. There are three pre-injections, one main injection and four post injections. Headline outputs are 381PS and 740Nm, the latter figure from 2000rpm. Overall NEDC fuel economy is 44.1 mpg, equating to 169g/km CO2. The use of urea injection and selective catalytic reduction, which BMW calls Blue Performance technology, allows the 750d to meet the forthcoming EU6 emissions regulations.

Below the 750d comes the 740d, with two turbochargers and 200MPa injection. Like both of the other diesel units, it uses piezo-electric injectors. At 313PS, the maximum power output is 7PS higher than its predecessor’s; peak torque of 630Nm is up by 30Nm and is available from 1500rpm. Overall rolling-road fuel economy has improved by 17 per cent. at 49.6mpg. This is equivalent to 149g/km CO2.

With 258PS and 560Nm, the entry-level 730d uses a single turbocharger and 180MPa injection. Maximum power has increased by 13PS, torque by 20Nm. NEDC fuel economy at 50.4mpg overall is only fractionally better than the 740d, though its outputs hardly suggest that the 730d is underpowered. It is available with an SCR system to meet EU6 emissions regulations.

The Active Hybrid 7 has a new engine and reduced fuel consumption. Power is now provided by a 320PS version of the unit fitted in the new 740i, replacing the V8 used previously. The electric motor is a 55PS synchronous device, fitted inside the housing of the eight-speed automatic gearbox. The battery-pack is lithium ion; we can’t quote its capacity at present, but it is a relatively lightweight unit. The hybrid Seven is not intended to run very far or very fast under battery power: the car can cover a distance of up to four kilometres at a maximum speed of 60km/h. The total system output is 354PS and 500Nm; overall NEDC rolling-road fuel economy comes out at 41.5 mpg, equivalent to 158g/km of CO2. That certainly means the more powerful hybrid technology uses some 14 per cent less fuel than a BMW 740i with a conventional drive system, but in pure mpg terms the 740d (with 630Nm) beats it, at 49.6mpg. The diesel’s denser fuel means that the advantage is smaller than it looks, but the 740d’s 149g/km CO2 yield is still better than the hybrid’s 158g/km.

The electric motor contributes 210Nm of torque to the hybrid’s drivetrain, and this is available from the first revolution of the motor.

One of the more significant aspects of the Active Hybrid 7’s specification is its Eco Pro driving mode, which incorporates with a coasting function and proactive analysis. This has universal significance, because it uses GPS information and other map data to prepare the car’s drive system in advance for upcoming situations on the road. This system is clearly not of use only to a hybrid car.

Finally, the 750d xDrive and 730d offer the option of EU6-specification engines, using what BMW calls Blue Performance technology — selective catalytic reduction using urea injection. A small amount of Diesel Exhaust Fluid, which is 32.5 per cent. urea in deionised water, is injected into the exhaust ahead of a catalyst. The urea thermally decomposes to ammonia, which reduces NOx to nitrogen (N2) and water in the catalyst. The quantity of DEF injected is quite small — around one fiftieth the quantity of diesel used. Many truck engines use this system, and as a consequence the DEF is widely available from filling stations, albeit in rather big bottles.

Chassis

The basic layout of the 7-series’ running gear has not changed, nor did it need to be changed. At the front are double wishbones made from aluminium, while a multi-lint set-up is used at the back; this also is aluminium. Air springs with a self-leveling function are used at the rear. There have been small changes in the interest of improved ride quality: rubber bushes and dampers have been revised, as have the ball joints. Hydraulic dampers are stiffer. In the words of the engineers, the elastokinematics have been revised.

The braking system is backed up by various state-of-the-art electronic safety systems which are integrated into the Dynamic Stability Control (DSC) package — the Anti-lock Braking System (ABS), Automatic Stability Control (ASC), Dynamic Traction Control (DTC), Dynamic Brake Control (DBC) and Cornering Brake Control (CBC), along with Start-Off Assistant, a brake drying function and an electronic limited slip function for the rear differential, which can be activated using the ‘DSC Off’ button.

The 7-series offers an electronically controlled damping system whose dampers are adjusted at each wheel individually according to the condition of the road surface and the driving style. The compression and rebound settings are adjusted continuously and independently from one another. For example, a stiff chassis setting can be combined with comfortable responses to unevenness in the road surface. The damper settings can be pre-set by the driver using the Driving Experience Control switch.

The Dynamic Drive roll stabilisation system available for the Seven reduces, among other things, body roll in high-speed corners and under sudden changes in direction. Sensors detect the amount of body roll and this is then counteracted by rotary actuators in the front and rear anti-roll bars. The car’s steering behaviour and load alteration effect are also adjusted as required in this way.

As we would expect, the 7-series offers the driver a choice of driving modes, by way of its Driving Experience Control switch. There is an Eco Pro mode, as well as modes for extra sporty or normal driving. The distinction between the different driving modes is now more pronounced than previously.

Using the Driving Experience Control switch, the driver is able to customise accelerator response characteristics, engine response, power steering characteristics and the Dynamic Stability Control (DSC) thresholds. Added to which, the Servotronic function, Integral Active Steering, the automatic transmission and Dynamic Damper Control are integrated into the system too. Using a rocker switch on the centre console, drivers can choose between Aco Pro, Comfort, Sport and Sport+ modes. If the Integral Active Steering option has been specified, Comfort+ mode is also available. This mode gains rear passengers, in particular, a noticeable improvement in ride comfort.

Another button allows the driver to change the DSC settings. Selecting Traction mode, for example, makes it much easier to pull away on loose surfaces or in deep snow. In this mode, as well as in Sport+, the Dynamic Stability Control thresholds are raised and Dynamic Traction Control (DTC) is activated. It is also possible to switch off DSC altogether.

The new Eco Pro mode with the addition of coasting and proactive driving assistant functions helps the driver to maintain an efficient and economy-conscious driving style. It does this by changing the accelerator mapping so that the same pedal travel delivers less power than in the standard mode. (Clearly, the driver is press to shove it harder.) Also in this mode, the transmission control strategy for the automatic gearbox is modified to bring forward upshifts and delay downshifts, while intelligent energy and climate management reduces mechanical power consumption and also the energy consumption of electrical systems such as heated mirrors and seats.

But the biggest factor influencing fuel consumption figures is the driver’s own personal driving habits. That is why electronic systems provide tips and incentives on how to develop a more economy-conscious driving style for the situation at hand. Special displays in the instrument cluster let the driver know by how much the driving range is being extended and indicate his fuel consumption history. The coasting mode, proactive driving assistant and Eco Pro Route can save a claimed five per cent., based on an internal BMW study.

All new rear-driven 7-series models come equipped with Electronic Power Steering (EPS). Models with X-Drive stick with a electrohydraulic arrangement.

Integral Active Steering is an option for rear-wheel drive Sevens. It combines the Active Steering system for the front wheels familiar from other models with a steering rear axle. The steering angle and power assistance are controlled at both the front and the rear with the help of electric motors. A system control unit processes information on wheel rotation speeds, steering wheel movement, yaw rate and lateral acceleration to shape the steering behaviour at the rear wheels. In addition, Integral Active Steering works with a variable steering ratio on the front axle.

In Comfort+ mode new software gives the car more strongly damped responses. This translates into a perception of greater comfort when changing lanes and driving through corners.

EfficientDynamics

All 7-series cars, with the exception of the 12-cylinder version, come equipped with a stop-start function. The standard specification also includes brake energy regeneration; the converse of this is that, when the engine is under load, the alternator can often be disengaged completely.

The coasting mode, proactive driving assistant and Eco Pro Route functions can save a claimed five per cent. The coasting mode and advance preparation of hybrid drive system are new functions. Coasting mode is designed to decouple the combustion engine when it is overrunning at speeds between 50km/h and 160km/h (31mph-100mph). In coasting mode, the car is freewheeling with no engine braking and minimal fuel consumption. In this way the kinetic energy built up by the vehicle can be harnessed and — through a forward-thinking driving style, aided by the car’s proactive driving assistant — fuel savings of up to five per cent are possible. The coasting function is clearly visualised for the driver’s benefit in the multifunctional instrument cluster and the central control display, and can also be deactivated if desired.

Drawing on the latest navigation data, the proactive driving assistant recommends advance adjustment of the car’s speed with the aim of saving fuel. These tips for more efficient driving are shown in the multifunctional instrument cluster and in the central control display. The BMW Active Hybrid 7 is also able to coast. In this case, the combustion engine switches off completely when overrunning. The system of intelligent energy management allows proactive analysis of the driving situation ahead with the aim of priming the hybrid drive components for maximum efficiency. This is achieved by integrating the power electronics with the standard-fit Professional navigation system. Based on the data gleaned in this way, such as route topography, speed limits or traffic levels, the vehicle can be prepared in advance and the available energy deployed as efficiently as possible. For instance, a long downhill stretch can be used to recharge the hybrid battery so that the vehicle can be driven on purely electrical power through a residential area on the home straight.

On-demand control of ancillary units is now familiar, and is a feature of the Seven. The include the coolant pump, the electronically controlled oil pump and the new electric power steering system, which offers potential savings of up to three per cent. The disengageable air conditioning compressor works on the same principle.

The car’s underside is panelled to reduce drag and lift. Also, the front aprons are designed to create an ‘air curtain’ effect which reduces turbulence around the front wheels.

BMW ConnectedDrive

The latest generation of BMW’s Professional navigation system is fitted as standard. It uses 3D menu displays and features a dictation function for emails and text messages, sending of voice memos by email, interactive map functions (PIE menu) and the simultaneous coupling of two phones. Optional is a multifunctional ‘virtual’ instrument cluster display with a range of instrumentation graphics.

Among the car’s driver assistance systems is a new Night Vision function with Dynamic Light Spot and the anti-dazzle High-Beam Assistant. Also available are Driving Assistant Plus and Active Protection with attentiveness assistant. More familiar is the Speed Limit Info function with No Passing Info — the camera reads speed limit signs and no passing signs and presents miniature versions of them on the dash or the head-up display. Also familiar from other cars is the Bosch Parking Assistant that parks your car for you — almost — by operating the steering and issuing instructions while you work the pedals. On a more prosaic level, the Comfort Access function allows hands-free opening of the boot lid.

Professional navigation system

The menu navigation has been consciously retained and augmented by new functions. The user interface has benefited from a complete graphic revision and now comprises 3D elements throughout, while the entire architecture of the individual menus is now presented in virtual, three dimensional spaces. The system has a 1.3GHz processor and dedicated 3D graphics card.

Along with the menu presentation, the navigation displays have been revised. The map displays and guidance information are now depicted with greater brilliance and sharpness than before. Additional function bars allow the map view to be customised quickly and simply without having to leave the map: the new function bars are superimposed as an extension of the original map bar and open up further options. This allows for Real Time Traffic Information (RTTI) or weather updates to be superimposed, POIs to be displayed, or the map to be rapidly switched from top view to perspective view. Standardisation of the control bars in the multimedia sphere alows the operation of a wide range of audio sources.

The interactive map view also comes with the option of selecting special functions directly from the map: using the iDrive Controller, the driver can mark a spot in the interactive map to open the PIE menu. This radial menu offers quick and easy access to a host of options. Depending on the information stored, the driver can have POIs in the area flagged up, read up on any stored details, start navigation to any of the points, alter the map view and have the current location or destination displayed. If further information on a POI — a telephone number, online data or an email address, for example — is also stored, the driver can instantly access these and make a call, visit a web-site or compose an email.

The split screen in the central information display also comes with added functions. To help orientate the driver while entering a destination, the chosen location is additionally displayed in the map view on the split screen. If required, the zoom function can be used to verify whether the destination shown in the relevant section of the map is the intended one.

For the navigation process itself, the familiar low-level guidance via arrows in the split screen has now been joined by a high-level guidance variant. This is automatically activated when the driver reaches a certain point ahead of the next navigation instruction. From a specified distance, which varies according to the category of road, the arrow display turns into a schematic, perspectival view of the surroundings, offering the driver better orientation thanks to its superior depiction of the location and precise lane guiding. For a better picture, the perspective view changes in stages to a top view of the junction or intersection as the vehicle approaches it, while a dynamic vehicle indicator pinpoints the car’s current position.

Then there is the 3D city model option. If the relevant representation of the city is stored in the car, a realistic depiction of the surrounding streets and houses makes it easier for the driver to find his way around.

The latest generation of Professional navigation system features a full speech recognition function and voice control system.

The dictation function gives drivers the opportunity to compose text messages simply by saying what they wish to write. A few seconds after dictation has been completed, the transcribed text appears in the display and can be read out if desired. As you would expect, drivers also have a number of simple editing tools available to them for putting the final touches to emails and SMS messages easily and, most importantly, safely. The multilingual system can recognise six languages.

A further speech-based option to enhance office functionality is voice memos, which can be sent directly by email if required. The advantage to the motorist is the ability swiftly to store ideas or to-do items and send them to the relevant addressees without being visualy distracted from what’s happening on the road — though we question whether visual distration is the only kind. The recorded memos can be stored on a USB stick for use outside the car.

Following the pattern of entering a destination with a single voice command, the voice control feature of the Professional navigation system now allows all menu functions to be called up through simplified voice commands. If you want to make a phone call, for instance, all you need to say is ‘Call John Smith.’ The system recognises that you wish to make a call and, after asking for verification of the number, makes the connection. A further advantage is the system’s ability to recognise contact data irrespective of the format in which they are stored, and thus independently of first name and surname order. Also, all submenu functions can now be activated or actions specified by speech input — from adjusting the radio and entering a destination to changing the route criteria.

Rounding off the new office functions is the facility for simultaneously coupling two phones to the car. The contact data of both phones are transferred to a shared list which is then available for making phone calls and sending e-mails. High-performance hardware means that calendar and contact information is displayed quickly, ensuring that both phones are quickly ready for use in the vehicle.

Multifunctional instrument cluster display

In place of the classic instrument cluster in which four circular analogue dials inform the driver of road speed, engine speed, tank level and oil temperature, the new BMW 7 Series now offers the option of a multifunctional ‘virtual’ instrument display. The basic layout with four circular dials is retained, while a virtually invisible 23cm integrated screen allows the display to change according to the driving mode selected. Comfort, Sport and Eco Pro each delivers its own style of display, based around the four-dial format. In addition to colour differentiation, the information content of the instruments is also varied according to the driving mode selected.

BMW Night Vision helps in spotting pedestrians as early as possible using Dynamic Light Spot. At the heart of the Night Vision system is an infrared thermal imaging camera integrated into the BMW kidney grille. This provides a live video image which clearly highlights any objects giving off heat, despite being far beyond the range of the high beam. The system recognises pedestrians, cyclists and animals in plenty of time, even when they are outside the headlights’ beam of light. The automatic pedestrian recognition control unit then analyses the image to determine whether the vehicle is on a collision course with any pedestrians or cyclists. If a person at the roadside is deemed to be potentially at risk, a high-resolution icon will flash up in the central Control Display or the BMW Head-Up Display as a warning. In addition to the visual and audible warnings, Dynamic Light Spots are now used to pinpoint the detected objects, allowing the driver to make out any road users in danger in the dark and react in time. The new LED headlights are fitted on the outsides of the front apron in place of the foglamps, and are computer-controlled to swivel and illuminate the target object precisely. The High-Beam Assistant also intervenes if required to prevent the Dynamic Light Spots from dazzling other traffic. When they are not activated, the Dynamic Light Spots are dimmed to work together with the daytime running lights or low beam.

As we have mentioned, the 7-series is now available with the option of full-LED headlights. The bright white light they emit illuminates the road ahead with an exceptional intensity. Together with the High-Beam Assistant, the adaptive headlights with cornering lights as well as variable headlight distribution, they represent what BMW claims is the ultimate in lighting technology. The anti-dazzle High-Beam Assistant avoids having to switch manually between high and low beam. The system uses a camera integrated into the rear-view mirror to identify vehicles travelling up to 400m in front. Oncoming traffic is picked up when it is still 1km away. With the High-Beam Assistant activated, the headlights are partially masked as and when required in order to eliminate the danger of dazzling vehicles as they draw closer. If necessary, however, the High-Beam Assistant can also adapt to the traffic situation by switching to low beam on one or both sides.

The active cruise control system Driving Assistant Plus builds on the familiar cruise control system with Stop & Go function. For a better interpretation of the traffic situation ahead, the full-range radar sensors are now supplemented by a front-mounted camera on the rear-view mirror. When driving in heavy traffic or in traffic jams, the driver is able to move safely along with the flow and let the vehicle’s automatic systems handle the tasks of stopping and pulling away again as well as approaching junctions where there are already vehicles waiting ahead. Combining radar and video data in this way improves detection of other vehicles and cuts the system’s reaction time. If a vehicle ahead brakes very sharply in free-flowing traffic, requiring the driver to take action, he is prompted to do so by a two-stage warning. Simultaneously to this, the activation thresholds of the Brake Assist system are lowered, activating the brake priming function in the process. If the driver fails to react to the warning, Driving Assistant Plus will intervene to decelerate the vehicle, even braking it to a stop depending on the situation. With Driving Assistant Plus, the upper limit of the operating range for the Active Cruise Control with automatic distance control has now been increased by 30km/h, meaning it is available at speeds between 30km/h and 210km/h (19mph and 130mph). The intelligent cruise control function continues to be active at speeds above 210km/h.

The Seven now boasts a more sunstantial active protection safety package thanks to the addition of the Attentiveness assistant. The system’s electronics analyse driving behaviour on the basis of various signals, such as steering angle, road speed and engine parameters. If the system increasingly detects telltale signs of fatigue starting to build up, the central control display encourages the driver to take a break by displaying a coffee cup symbol.

At the start of every journey, when the driver and front passenger fasten their seat belts, the Active Protection motorised belt retractors reduce any belt slack.If the car enters a critical pre-crash scenario, the driver and front passenger belts are pulled tight, and the side windows and sunroof are closed. Active Protection deduces that a collision is likely based on data from the front-mounted camera or radar, an emergency braking manoeuvre initiated by the driver, or the onset of heavy understeer or oversteer. If a crash is unavoidable, the system will automatically brake the car without any intervention required from the driver. Following the initial impact, the car is slowed to a standstill with a maximum deceleration rate of 5m/s² and its brakes are then locked for a further 1.5 seconds. This reduces the likelihood of — or even prevents — a secondary or domino collision.

In combination with the Professional or Business navigation system, Speed Limit Info keeps the driver notified of the detected speed limit for the current stretch of road. The front-mounted camera integrated into the rear-view mirror continuously monitors road signs, including variable-message overhead signs on motorways and dual carriageways. This information is checked against the navigation system’s database of speed limits. The camera is also able to take into account additional signs or temporary restrictions — for example, at roadworks. As with speed limits, a No Passing display can now also be flashed up in the instrument cluster or the head-up display in the form of a road sign until the restriction has been lifted. Also, drivers now have the benefit of a Speed Limit Device, which can cap the car’s maximum speed at between 30km/h and 230km/h, as set by the driver.

Parking Assistant uses ultrasonic sensors integrated into the sides of the vehicle to help search for suitable parking spots. The system then helps the driver to manoeuvre into parking spaces positioned parallel to the direction of travel. With the Parking Assistant activated and the car travelling at a slow speed of no more than 35km/h, a notification appears in the control display to alert the driver to suitable spaces that are at least 1.2m longer than the 7-series as it passes them. During the parking process, all the driver has to do is change gear, operate the accelerator and brake pedal, and keep an eye on the area around the car. The Parking Assistant takes care of all the steering movements required to execute a precise reverse parking manoeuvre. A new bird’s-eye view of the vehicle in the control display works in unison with the Park Distance Control to visualise the distance to other objects and make it easier for the driver to monitor the parking process.

The 7-series now offers a hands-free boot-lid opening function. Standing behind the car, a quick movement of the foot under the rear bumper is enough to prompt the boot to open without any use of the hands. The boot lid then automatically unlocks and swings open by spring force. For detection purposes, the vehicle is fitted with sensors placed at different heights in the rear bumper trim. The sensors can identify the foot ‘command’ by monitoring the area of the leg between the shin and the tip of the foot. They then send a signal to the onboard computer. Access is only authorised if the system simultaneously identifies the Comfort Access control unit (the key), which the person must be carrying with him. The boot lid is then unlocked and raised automatically, without hand contact.

Body and safety

It is no surprise to find aluminium in the Sebener’s structure, but BMW does not go so far as Audi — to say nothing of Jaguar — in its use of lightweight materials. Much of the body is steel, though the roof is aluminium, bonded to the steel body using adhesives. The aluminium panel saves seven kilograms over a steel roof. Additionally, the bonnet, front side panels, front spring struts and doors are also made of aluminium. The use of aluminium for the doors shaves 22kg or so off their weight.

Body strength (left undefined by BMW) has been increased by around 60 per cent. compared to the previous car, while torsional stiffness is now some 20 per cent higher. No figure is given.

Depending on the nature of a crash, integrated safety electronics ensure that only those airbags that are able to provide effective protection are actually deployed. Airbags that are not required therefore continue to be ready for action in the event of a possible secondary collision.

To guard against whiplash injuries following a collision from the rear, the front seats are fitted with crash-activated head restraints as standard. These are controlled by the safety electronics. In the event of a rear-end shunt, the system responds by causing the front part of the head restraint to shoot forwards by up to 60mm and upwards by a maximum of 40mm. The effect of this is to narrow the distance to the occupant’s head before it starts to be thrown back by the force of the impact. Active head restraints reduce the risk of sustaining cervical spine injuries or hyperextension.

The most noteworthy accident prevention features include the new full-LED headlights with anti-dazzle High-Beam Assistant; Adaptive Headlights including cornering lights and variable light distribution; Active Protection with Attentiveness assistant featuring an eCall function and automatic vehicle location; plus, to limit the risk of rear-end collisions, adaptive brake lights. If the driver brakes very heavily and the ABS system cuts in, the LED brake lights flash conspicuously as a warning to following drivers that they too should take appropriate action. After the vehicle has been braked to a particularly sharp stop, the hazard warning lights switch on automatically.

Inside

The front seats are newly designed and more slender than previously. This is relative, though. They are substantial.

Sports seats and multifunction seats are also available. The latter can be ordered with a folding table in the backrest or with the Rear Seat Entertainment package as an option. A brand-new feature are the 23cm screens which, instead of being integrated into the front seats, sit slightly proud of them. Their design takes its inspiration from the latest breed of flat-screen monitors.

The new BMW 7 Series can be specified as an option with individual, adjustable rear seats. The backrest angle and seat position can both be varied, as can the position of the head restraints. The controls are the same as those for the front seats and have a memory function.

All of the long wheelbase car’s extra 140mm are used to provide more space for the rear passengers. Additionally, changes to the roofline of the long-wheelbase version create 10mm of extra headroom in the rear.

So far as refinement goes, additional insulation materials have been added in the B- and C-pillars, in the skirts and the boot area.

Predictably, the sound system is wildly powerful. The 1200W system is hooked up to 16 speakers, some of which are positioned behind illuminated, satin-finish aluminium grilles sited in the mirror triangles of the doors and the parcel shelf. Particularly attention-grabbing is the illuminated centre speaker which extends out of the instrument panel and uses B&O Acoustic Lens technology. When the music system is switched off, the centre speaker retreats back into the instrument panel.

There is new ambient lighting for the interior — pleasant for the passengers no doubt, but distracting for the driver. There are footwell lights for the driver and front passenger and indirect roof liner illumination using lights integrated into the B-pillars.

We have mentioned the optional ‘vitual’ instrument display and its ability to adapt to the selected driving mode. Comfort mode brings a classic layout with four solid circular instruments. In Eco Pro and Sport modes, the rings open to offer additional space for extra information between the two main instruments. In Eco Pro mode the display turns blue and the rev counter morphs into an Efficient Dynamics display to show how efficiently (actually how gently, which is not always the same thing) the car is being driven. If the system deems that the driver is pressing too forcefully on the accelerator, the full display turns grey and alerts them to the amount of fuel they are burning. A speedometer zoom function can also be activated in Eco Pro and Comfort modes. This enlarges the position of the speedo needle as if a magnifying glass were being passed over it, making it even easier to see.

In Sport mode the display takes on a signature BMW orange hue. This display mode purposefully retains a very puristic look and only shows the driver the most essential information, so that he can maintain maximum concentration on the road ahead. The speedometer shows the car’s speed in digital form only with a large, centrally positioned figure, while the gear currently engaged is boldly displayed in the middle of the rev counter if the driver is shifting manually using the steering wheel paddles. As well as the changes in colour, the displays in the instrument cluster also deliver additional information tailored to the situation at hand — such as status and function updates, check and control messages and navigation instructions, which drivers can call up as and when they wish.

Production

The BMW 7 Series has been built at Dingolfing since it was launched in 1977. BMW’s largest production plant worldwide has been part of the global BMW production network, which now includes 29 factories in 14 countries, since 1967. Dingolfing is also home to the BMW Group’s Aluminium Competence Centre. Special process engineering has been developed exclusively for the 7-series with the aim of combining its aluminium roof with the steel body. The result is the use of a new, high-tech adhesive. This material offers an extremely high level of flexibility under heat-induced expansion. The door bodies consist of just two components, which are laser-welded together.

As well as the roof and doors, the bonnet, front side panels and front spring struts are also made from aluminium. Various joining technologies — such as bonding, riveting and MIG welding — are used in the construction of the front-end structure according to need and the loads each component will be subjected to.

The delivery of pre-assembled modules, or sub-assemblies, in completed form provides a particularly valuable helping hand to the processes at the production line. The finished front-end construction, for example, is delivered to the line just-in-sequence as an individual module. This means that fewer process stages are required when it gets there. Plus, the bodyshells can be produced in any order and mixture, according to instructions from the production management system.

Note that the data table below is not exhaustive.

BMW 740i 750i 760Li 730d 740d 750d
X-Drive
Active
Hybrid 7
Cylinders 6I 8V 12V 6I 6I 6I 6I
Block/head Al/Al Al/Al Al/Al Al/Al Al/Al Al/Al Al/Al
Valves 4 4 4 4 4 4 4
VVT IE IE IE IE
Aspiration 2T 2T 2T Tv 2T 3T 2T
Injection/
pressure
d
d
d
d
180MPa
d
200MPa
d
220MPa
d
Bore/stroke 84.0/89.6 89.0/88.3 89.0/80.0 84.0/90.0 84.0/90.0 84.0/90.0 84.0/89.6
Swept volume 2979cc 4395cc 5972cc 2993cc 2993cc 2993cc 2979cc
Compression
ratio
10.2:1 10.0:1 10.0:1 16.5:1 16.5:1 16.5:1 10.2:1
PS/rpm 320/5800 449/5500 544/5250 258/4000 343/4300 381/4400 320/5800
Nm/rpm 450/1300 650/2000 750/1500 560/1500 630/1500 740/2000 450/1300
Maximum speed 155 155 155 155 155 155 155
0-100km/h 5.7 4.8 4.6 6.1 5.5 4.9 5.7
Urban MPG
(l/100km)

(10.6)

(11.9)

(19.6)

(6.8)

(6.9)

(7.3)

(6.0)
Combined MPG
(l/100km)

(7.9)

(8.6)

(12.8)

(5.6)

(5.7)

(6.4)

(6.8)
CO2 g/km 184 199 299 148 149 169 158
Emissions EU5 EU5 EU5 EU5 (EU6) EU5 EU5 (EU6) EU5
Transmission
— I
— II
— III
— IV
— V
— VI
— VII
— VIII
— Final drive
A8
4.714
3.143
2.208
1.667
1.285
1.000
0.839
0.667
3.077
A8
4.714
3.143
2.208
1.667
1.285
1.000
0.839
0.667
2.813
A8
4.714
3.143
2.208
1.667
1.285
1.000
0.839
0.667
2.813
A8
4.714
3.143
2.208
1.667
1.285
1.000
0.839
0.667
2.813
A8
4.714
3.143
2.208
1.667
1.285
1.000
0.839
0.667
2.647
A8
4.714
3.143
2.208
1.667
1.285
1.000
0.839
0.667
2.813
A8
4.714
3.143
2.208
1.667
1.285
1.000
0.839
0.667
2.929
Driven wheels Rear Rear Rear Rear Rear All Rear
Fuel tank 80l 80l 80l 80l 80l 80l 80l
Kerb mass † 1825 1940 2175 1840 1865 1995 1970
PS/t 175 231 250 140 184 191 162
Nm/t 246 335 345 304 338 371 228
Tyres 245/50R18 245/50R18 245/50R18 245/55R17 245/50R18 245/50R18 245/50R18
Steering
— type
— ratio

E
17.1:1

E
17.1:1

E
17.1:1

E
17.1:1

E
17.1:1

H
19.1:1

E
17.1:1
CdxA 0.28x2.42 0.28x2.42 0.30x2.42 0.28x2.42 0.28x2.42 0.30x2.42 0.28x2.42
Dimensions See graphics below
† DIN kerb mass. For E.U. kerb mass, add 75kg.
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