Saturday, January 5, 2008

New BMW X5 in Depth




Page 1: Short Version (I)
Page 2: Short Version (II)
Page 3: The Concept
Page 4: Driving Dynamics
Page 5: All Wheel Drive
Page 6: Power Units
Page 7: Automatic Transmission
Page 8: Exterior
Page 9: Interior
Page 10: Body & Safety
Page 11: The iDrive Control System
Page 12: Features and Equipment (I)
Page 13: Features and Equipment (II)
Page 14: Production
Page 15: Specifications



Driving Dynamics

  • Unique double wishbone front axle.

  • World’s first SAV with Active Steering and AdaptiveDrive.

  • DSC with additional functions for enhanced driving dynamics.

Right from the start in developing the new BMW X5, the guiding force was to enter new dimensions in driving dynamics. Accordingly, powerful engines acting with enhanced precision are the major factors raising the high standard of the former model to an even higher level of performance, agility, dynamics, and suspension comfort.

An all-new development, for example, is the suspension conveying the power of the engine to the road – or to rough terrain – with impressive supremacy. This unique suspension is then supplemented by numerous innovations featured for the first time in an SAV Sports Activity Vehicle – such as optional Active Steering with Servotronic as well as optional AdaptiveDrive with anti-roll stabilisers and adaptive dampers.

Wide track, long wheelbase – simply ideal for superior driving dynamics.

The new BMW X5 naturally retains the basic principles of a unitary bodyshell, independent suspension, and permanent all-wheel drive. And while the exterior dimensions of the new model are larger than before, the fundamental proportions remain the same and the overall weight of the vehicle has hardly changed.

These factors alone give the new BMW X5 ideal dimensions for a further enhancement of driving dynamics borne out in particular by the wider track and longer wheelbase: This applies particularly to the even wider track of the new BMW X5 now measuring 1, 644 millimetres or 64.72´´ (+ 68 millimetres or 2.68´´ ) at the front and 1, 650 millimetres or 64.96" (+ 74 millimetres or 2.91´´ ) at the rear. Wheelbase, in turn, is up by 113 millimetres or 4.45´´ to 2, 933 mm or 115.47´´.

The new BMW X5 is the first BMW to boast a double wishbone front axle offering ideal conditions for outstanding supremacy at all times combined with the further enhancement of driving dynamics. The result is truly outstanding lateral acceleration, superior directional stability all the way to high speeds, minimisation of bumps and impact forces acting on the steering wheel as well as body roll of the entire vehicle, with the front axle offering outstanding smoothness and ride control.

Given this wide range of qualities, the new double wishbone front axle guarantees not only sheer driving pleasure of the highest calibre, but also a high standard of safety, excellent qualities in everyday motoring, and a relaxed style of driving also on long distances.

Perfect road contact for high lateral acceleration.

Several interacting features and technologies serve to provide these benefits. The kinematic configuration of the double wishbone front axle, for example, keeps front wheel camber exactly right at all times, with the tyres maintaining optimum ground contact in every situation. This, in turn, enables the tyres to convey higher lateral forces for significantly greater lateral acceleration than in the case of a conventional front axle. A further positive effect is that the double wishbone front axle helps to enhance the vehicle’s directional stability all the way to top speed, the specific configuration of the axle’s kinematic levers minimising the transmission of impacts to the steering wheel when crossing dividing lines on the road, passing over pitholes or bumps.

On the double wishbone front axle the dampers are not required to guide the wheels and are therefore not exposed to any lateral forces, thus showing particular smoothness and sensitivity in responding to bumps on the road surface.

A further decision taken by the development engineers was to attach the anti-roll bar directly to the wheel mounts for a significant increase in smoothness and performance. Indeed, the combination of these improvements gives the new BMW X5 very supple spring and damper response, reducing body roll to a minimum even in dynamic bends.

Integral-IV rear axle for superior transmission of power.

The integral-IV rear axle in lightweight construction patented by BMW and enhanced to an even higher standard in the BMW X5 also makes its contribution to optimum driving dynamics. Indeed, the entire configuration of the rear axle has been specifically tailored to the dimensions of the new BMW X5 and the extra power of the engines.

Through its concept and configuration, the new integral-IV rear axle benefits both driving dynamics and motoring comfort, the wheel mounts, rear axle subframe and four track control arms taking up the dynamic and drive forces flowing into the suspension. This reduces any elastic tension acting on the wheel mounts, while at the same time the soft swing-arm supports provide exactly the right kind of longitudinal wheel guidance crucial to superior roll comfort.

This optimum longitudinal spring action is highly effective in isolating roll and drive noise, making a particularly significant contribution to superior smoothness and noise control in the new BMW X5. Self-levelling controlled by the air springs on the rear axle maintains consistent ride height and driving characteristics at all times, regardless of the load the new model is carrying. This self-levelling suspension is standard on the BMW X5 4.8i and is available as an option on the six-cylinder models.

Making its debut in the SAV segment: Active Steering with Servotronic.

The new rack-and-pinion steering with its variable transmission ratio (between 55 and 62 millimetres/2.17 and 2.44´´ on each turn of the steering wheel) as a function of the steering angle caters for all requirements and driving conditions. When driving straight ahead, the steering helps the driver through its intentionally more indirect transmission ratio to handle the vehicle in superior style all the way to very high speeds, while in bends it is more direct in support of a dynamic style of motoring.

The new BMW X5 is the first vehicle in its class optionally available with Active Steering. Specially configured for BMW’s SAV, Active Steering helps in a large number of driving situations to capitalise even more than before on
the dynamic potential of the BMW X5.

The first factor to be mentioned in this context is optimisation of the transmission ratio for all speeds: At speeds of up to approximately 90 km/h or 55 mph, the steering transmission ratio is very direct, providing a significant advantage particularly for a sporting and active style of motoring and hardly requiring the driver to cross over his arms on the steering wheel.
In parking manoeuvres, for example, all the driver has to do is turn the steering wheel twice when moving from the extreme left to the extreme right lock.At high speeds, on the other hand, the steering becomes increasingly indirect in the interest of precise directional stability and superior motoring comfort.

Active Steering for enhanced driving stability.

Active Steering in the new BMW X5 is combined with Servotronic. While Servotronic determines the steering forces required at any given point in time, Active Steering specifies the steering angle required, in each case as a function of road speed.

Both of these systems supplement each other in an ideal manner, not only in terms of driving dynamics, but also in the interest of enhanced safety. For apart from benefits in driving dynamics, Active Steering also makes an important contribution in stabilising the vehicle when oversteering in bends, quickly and precisely countersteering and stabilising the vehicle in the process. The same countersteering effect serves when braking on different surfaces (with the wheels subject to different frictional coefficients) to prevent the vehicle from swerving out of control, thus maintaining driving stability at all times.

AdaptiveDrive for unique supremacy in the SAV segment.

Yet another unique feature in the SAV segment is coordinated control and management of the anti-roll bars and dampers by AdaptiveDrive available as an option. Combining active anti-roll stability with variable damper control, AdaptiveDrive gives the new BMW X5 a standard of safety, comfort and agility quite unprecedented in its class. The system prevents body roll and dive in fast bends or dynamic manoeuvres when evading an obstacle or in similar situations.

AdaptiveDrive also serves to reduce the steering angle required and improves roll comfort while at the same time enhancing driving dynamics to an even higher level. And simply by pressing a button, the driver can opt for a more sporting or a more comfortable setting.

Using sensors specifically conceived for this purpose, AdaptiveDrive permanently measures and calculates the vehicle’s current lateral and longitudinal acceleration, road speed, the position of the steering wheel, body and wheel acceleration, as well as the ride height of the body.
Then, applying this data, AdaptiveDrive determines the appropriate commands for the swivel motors in the anti roll bars and the electromagnetic valves in the dampers.
Interacting with one another, these two control units serve instantaneously to prevent any imminent body roll of the vehicle.
A unique feature in this context is the coordinated interaction of the anti-roll bars and dampers, with the two halves of the anti-roll bars being disconnected from one another while driving straight ahead in order to prevent any undue harshness of the suspensions caused by spring action on one side only.

World debut: data transfer via FlexRay.

The new high-speed FlexRay data transmission system developed under the leadership of BMW controls the sensors and control units to transmit and process large amounts of data within fractions of a second. And now the new BMW X5 is the world’s first vehicle to feature this technology.

The FlexRay transmission system is used exclusively on the new BMW X5 to mastermind AdaptiveDrive and operates in parallel to the proven structure of the on-board network. The particular potential of the FlexRay system is its ability to transmit an unusually large volume of data within an extremely short time, thus making FlexRay absolutely excellent for networking the satellites used within the system of vertical and dynamic vehicle management.

To optimise the effect of AdaptiveDrive at all times, changes in driving and road conditions are monitored and registered by an enormous number of data, body and wheel acceleration as well as ride height all being registered parallel to one another and compiled in a central computer to provide one overall picture. This serves to determine the appropriate reaction in each case, transmitting the right signals to the anti-roll bars and dampers.

Determination of such a multitude of data all at the same time requires a particularly efficient, high-performance transmission system. And therefore FlexRay now offers BMW precisely the technology needed for even greater precision and superiority in dynamic driving control.

DSC with additional functions.

The additional functions of BMW’s optimised DSC Dynamic Stability Control also bear clear testimony to the progress made in this area, enhancing motoring comfort, driving dynamics and safety to a level never seen before.

The basic functions of DSC include stabilisation of the vehicle by intervention of the brakes and the reduction of engine power, efficient operation of the ABS anti-lock brake system, ASC Automatic Stability Control, HDC Hill Descent Control, Trailer Stability Control, DBC Dynamic Brake Control automatically maximising brake pressure whenever required for significant deceleration, as well as CBC Cornering Brake Control preventing any undesired oversteer of the vehicle when applying the brakes slightly in a bend.

A further function is the electronic ADB Automatic Differential Brake acting as a differential lock whenever required by automatically applying the brakes on a wheel threatening to spin.

Driving downhill with extra comfort thanks to HDC.

HDC Hill Descent Control, BMW’s intelligent system for driving downhill with absolute ease and comfort, offers significant advantages above all on rough terrain. Since driving down a steep gradient on loose or slippery ground may become a problem even for a vehicle with all-wheel drive, HDC activated at the touch of a button enables the new BMW X5 to successfully master even a challenge of this kind. So without requiring the driver to intervene in any way, the vehicle automatically applies the brakes as required on all four wheels, proceeding downhill at a steady, constant speed. And since this intervention by the brakes takes place within milliseconds, the occupants do not feel any discomfort of any kind.

HDC Hill Descent Control may be used at speeds of up to 35 km/h or 22 mph, the system switching over to the standby mode as soon as the driver exceeds this speed. At 60 km/h or 37 mph, in turn, HDC is automatically deactivated.

The driver himself is able to determine how fast the BMW X5 is to proceed when driving downhill, with automatic speed adjustment from 7–25 km/h (4.5–15.5 mph). And to terminate the HDC function, all the driver has to do is touch the brake pedal.

Maximum safety when towing a trailer.

A four-wheel-drive vehicle such as the new BMW X5 is simply perfect for towing a trailer. And to ensure maximum safety also under such conditions, BMW’s SAV is equipped with innovative Trailer Stability Control suppressing any dangerous instability and preventing any uncontrolled roll or pendulum motion of the tractor and trailer.

Recognising the risk of the vehicle and trailer starting to sway relative to one another at an early point, Trailer Stability Control re-stabilises the driving vehicle and trailer by quickly applying the brakes on both the vehicle itself and the trailer being towed, at the same time briefly reducing engine power to a minimum. Both of these steps are taken automatically by the system, without requiring any intervention on the part of the driver.

Trailer Stability Control is activated automatically as soon as the trailer is connected to the vehicle by the power cable. The minimum speed at which the system is able to intervene is 65 km/h or 40 mph.

The new BMW X5 is homologated for towing a trailer of up to 2,700 kilos or 5,954 lb. And as an option, maximum trailer load may even be increased to 3,500 kg or 7,718 lb on the BMW X5 3.0d and the BMW X5 4.8i. Optimum brake effect in every situation.

A further advantage of BMW’s new DSC Dynamic Stability Control is optimisation of the brake system in various ways and through a number of functions: First, DSC compensates any drop in brake power under extremely high brake temperatures by specifically increasing brake pressure as required and thus counteracting any kind of fading effect (anti-fading function). The second function is additional build-up of moderate brake power for enhanced brake standby in any kind of situation likely to require spontaneous deceleration. Regular Dry Braking, in turn, optimises brake performance under wet conditions as a function activated automatically as soon as the rain sensor registers such wet conditions or the driver switches on the windscreen wipers.

Last but not least, the new BMW X5 features a parking brake with both electromechanical and hydraulic operation activated or released easily and conveniently by means of a button on the centre console. Since even an all-wheel-drive vehicle can only capitalise on its enhanced traction when the power of the engine is really able to reach the wheels, the Start-Off Assistant is an ideal match for the new BMW X5, this additional DSC function holding the vehicle briefly in position after the driver has released the brake and thus avoiding the risk of rolling back when setting off on an uphill gradient.

DTC for enhanced slip and extra dynamics.

Reflecting its high level of driving dynamics, the new BMW X5 also comes with DTC Dynamic Traction Control, a special DSC mode tailored to the new BMW X5 and its specific requirements and activated simply by pressing a button on the centre console. Ideal for driving off the beaten track, DTC raises the response threshold for intervention by the engine and brakes, enabling the BMW X5 to set off smoothly and easily, for example, on loose snow or sand, with its drive wheels spinning slightly. And at the same time DTC allows an even more sporting and active style of motoring on the road, even with a slight, controllable powerslide in bends.

Supported by the many functions of BMW’s new Dynamic Stability Control, the high-performance brake system in the new BMW X5 allows excellent deceleration in all situations, inner-vented discs on all four wheels reliably taking up brake energy. Disc diameter on the BMW X5 3.0si is 348 millimetres or 13.70´´ at the front and 320 millimetres or 12.60´´ at the rear.
On the BMW X5 4.8i, in turn, the brake discs measure 365 and, respectively, 345 millimetres (14.37 and, respectively, 13.58´´ ) in diameter.

Cruise Control with brake function.

As an option, the new BMW X5 is also available with cruise control incorporating a special brake application function. The big advantage of this system is that it does not only maintain the speed preselected by the driver, but also reduces road speed whenever necessary under specific driving conditions.

Cutting in as of 30 km/h or 20 mph, cruise control with its brake function serves to maintain the speed preselected by the driver at all times, regardless of the route he is taking. To do this, the system either increases engine power automatically or, by cutting off engine power and shifting down the transmission, uses the brake force of the engine to reduce speed.
Should this reduction of speed not be sufficient, say, when driving downhill or towing a trailer, the system intervenes additionally in the brakes.

This advanced system of cruise control complete with its brake function comes in addition with a Curve Speed Limiter reducing the speed of the vehicle in bends to a lower level than desired whenever this is necessary on account of dynamic driving conditions. To determine when this necessity arises, the Curve Speed Limiter covers lateral acceleration data provided by the sensors, adjusting the speed of the vehicle whenever driving conditions become critical. Then the Curve Speed Limiter accelerates the BMW X5 again to the desired speed when leaving the bend.

The driver masterminds the cruise control function by means of a stalk on the steering column. As soon as the vehicle reaches the minimum speed required of 30 km/h, therefore, all the driver has to do is pull or press the control stalk to adopt his current speed at the desired level and then change such speed whenever he wishes. Cruise control with its brake function is deactivated either via the control stalk or by pressing down the brake pedal. Then, pressing the Resume button, the driver is able to activate the system again at the final speed saved in the system.

The Comfort Dynamic function enables the driver to use the control stalk for accelerating in the handgas mode, increasing the speed of the vehicle whenever he wishes in two dynamic stages and in an absolutely constant process, without pressing down the gas pedal.




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