Car Trend Magazine: May 2009

Sunday, May 31, 2009

M engines

Straight-six normal-aspiration power units are one of BMW's calling cards. In all M models (with the exception of the M5), engines of this type combine tremendous output and performance even at low engine speeds while delivering outstanding fuel economy and emission management.

Total consumption (combined): from 11.9 to 14.8 ltr/100 km. CO2 emissions combined:
from 287 to 357 g/km.

Further information on the official fuel consumption and on the official specific CO2 emissions of new automobiles can be found in the guidelines on fuel consumption and CO2 emissions of new automobiles which are available free of charge at all retail outlets and from DAT Deutsche Automobil Treuhand GmbH, Helmut-Hirth-Str. 1, 73760 Ostfildern-Scharnhausen, Germany.

The ten-cylinder engine with a capacity of five litres is the top engine in the BMW M family, thanks not only to the tremendous power produced by its 294 kW (400 hp) and the torque value of 500 Nm, but also to the Digital Motor Electronics (DME) which execute up to 25 million commands every single second.

It regulates the electronic throttle butterfly control, a system which converts every movement of the driver's foot into an engine command instantaneously. The electronic throttle butterfly control also takes care of M Servotronic and M double-Vanos.

In addition, the M high-revolution concept has been delivering that Formula One feeling for over twenty years. Combined with a similarly impressive transmission system, high-speed engines mean maximum strength with the accompanying full-bodied sound - the M3, for example, delivers between 1,000 and 8,000 rpm.
And against the odds, BMW have been able to keep the weight and size of the engine relatively low despite the massive increase in strength.

M double-Vanos

M double-Vanos (double-variable camshaft control) significantly improves the torque curve of the six-cylinder petrol engine. Valve timing both on the intake and outlet camshaft is adjusted to the power and torque required of the engine as a function of gas pedal position (load-related) and engine speed. And all this is done with infinite, diagram-controlled precision.

M double-Vanos requires very high oil pressure (approx. 80 - 120 bar) in order to adjust the camshafts as quickly and precisely as possible. This ensures supreme torque at low engine speeds and equally impressive output at high speeds.
The engine's idling qualities, in turn, are improved by the reduction of unburnt residual gases, and special engine management maps for the warm-up period enhance the efficiency of the catalytic converter.

Lightweight chassis

The lightweight chassis is created of aluminium, as are the aluminium integrated rear axle and the double-joint spring-strut front axle.

This ensures that the automobile's weight is kept at a minimum, thereby delivering excellent road-holding as well as excellent safety and precise handling.

ISOFIX

You can secure two child seats safely to the back seat of your BMW with the ISOFIX system. The child seats are firmly anchored to the vehicle's body via extendable mounting bars integrated into the seats.

Tilting or swaying of the seat is thus almost impossible. The mounting bars are located between the seat and the seat back and are barely visible. Adults travelling in the rear seats will in no way be inconvenienced by the ISOFIX system.

Intercooler

BMW diesel automobiles contain an intercooler, a special heat transferral unit in which the air compressed and heated by the turbocharger is cooled so it can be passed to the combustion chamber.

Cooler air contains more oxygen molecules: this enables the fuel to burn with increased efficiency, resulting in improved performance as well as lower fuel consumption and emissions.

Integrated seatbelts

The integrated seatbelt system, also known as the BMW restraint system, can reduce the force of an impact on a car's occupants by up to 50 per cent compared with conventional protection systems. Through the interaction of the seatbelt, belt latch tensioner, belt force limiter and anti-submarining protection on the seat itself, the BMW restraint system guarantees optimum protection in the event of a collision.

The belt latch tensioner, for example, incorporates a pyrotechnical actuator which retracts the belt latch within fractions of a second in the event of a collision, while at the same time tightening the shoulder and lap belts. Greater speed is a further advantage of this pyrotechnics-based control system, enhancing the efficiency of this safety system.

The anti-submarining protection, in turn, is a wedge-shaped component at the front end of the seat that helps to ensure that the driver and front passenger don't slip beneath the lap belt.

Info Display

Designed with practicality in mind, the Info Display can provide everything from the essential minimum of information to a detailed insight into the functioning of the vehicle. This is possible thanks to the combination of the high-resolution LCD screen and mechanical needles. Be it navigation information or the cruise control setting, you can see exactly what you want to know, when you want to know it.

Programmable cruise control can be activated at any speed above 30 km/h. Six different speeds can be pre-set and saved, and activated at any point in the journey.
Navigation is made so easy: arrows clearly show the way along the best route and up-to-the-minute traffic reports are also displayed.

The LCD screen can display status or warning lights for fourteen different features. From classics, such as "Please fasten your seat belt", to status reports on Dynamic Stability Control (DSC), Dynamic Traction Control (DTC) and Dynamic Brake Control (DBC), to world firsts such as Automatic Hold and the 7 Series parking brake.

ITS head airbag

The Inflatable Tubular Structure (ITS) head airbag and the side airbags, which both come as part of the standard fittings, combine to provide excellent side impact protection for the car's occupants. If hit from the side, ITS head airbags safeguard against the dangerous effect by which the occupants' heads are flung to one side and hit off the door (hyperflexion) and it prevents injury caused by objects entering the car.

The sides of these airbags are integrated with the frame of the roof and inflate instantly thanks to their honeycomb structure. When expanded, they cover the safety belt's height adjuster and front side windows diagonally, thereby delivering the best protection irrespective of the occupant's size or position in their seat.

Impact dampers

One important safety feature in every BMW is the sophisticated composite construction of hydraulic-pneumatic impact absorbers, mechanical impact elements and deformable side elements. The bumpers with their reversible aluminium impact dampers can absorb blows of up to 6 km/h without so much as a scratch.

Special deformation zones at the front and rear of the car can withstand impact speeds of 15 km/h; they keep repairs costs down as they can simply be replaced. Only at higher speeds do the engine supports begin to deform in a predefined way - they do so precisely to the extent necessary to protect any people involved in an accident as well as the vehicle itself.

iDrive

iDrive is an innovative control concept allowing the driver to use their car in an intuitive, interactive manner. The driving functions are separated from the comfort functions and as the number of switches and control units is reduced to a minimum, the driver is hardly distracted from traffic conditions.

To allow the driver to concentrate in full on road, all major driving functions such as the ignition starter switch, the start/stop button and the control switches are arranged around the steering wheel. Comfort functions such as the controls for the automatic air conditioning are in turn located in the middle, within direct reach of the driver and front passenger.

All the comfort functions can be operated intuitively with one hand using Control Display and the single input unit, the Controller.

All functions are subdivided hierarchically into primary (e.g. radio volume, windscreen wipers and cockpit temperature) and secondary functions (e.g. fuel consumption display).

Impact-Depending airbags

Several airbags protect the passengers of a BMW in the event of a collision.

The standard-fitting driver and front passenger airbags function according to the Impact-Depending (ID) system, which calculates the danger posed to the driver and front passenger by taking factors such as the strength of the impact into account; the airbag is then inflated the appropriate size.

HiFi Professional LOGIC7 System

Incorporating 13 loudspeakers, the HiFi Professional LOGIC7 System ensures supreme playback of all audio formats and takes the surround sound effect to an even higher level. Seven subwoofers, four tweeters and two woofers (central bass concept) provide an incomparable experience in sound.

The tweeters and subwoofers measuring 100mm or 3.94" in diameter feature aluminium membranes with an additional ceramic surface on the tweeter domes. Six subwoofers are arranged on the left and right in the front and rear doors and the rear window shelf, while one loudspeaker is located right in the middle of the instrument panel.

The two bass loudspeakers measuring 217mm or 8.54" in diameter are located beneath the left and right front seats. This central bass concept ensures symmetrical distribution of low frequency sound within the occupant cell. With the high-performance woofers being connected acoustically to the side sills, the hollows space inside these sills is used to provide particularly impressive sound volume.

A further advantage of this concept is that luggage compartment capacity remains the same, the linings and panels do not vibrate in any way and the reproduction of bass sounds is virtually free of any distortion.

HiFi Professional DSP System

The HiFi Professional DSP System is one of the central elements upon which the HiFi Individual High Audio System is based.

The DSP amplifier ensures that every amplifier channel and the accompanying speaker can be individually adjusted by computer for volume and frequency. The system guarantees the very clearest sound quality.

HiFi Individual High Audio System

The HiFi Individual High Audio System in the BMW M5 is based on the HiFi Professional DSP System and comes complete with a 14-channel amplifier and 290 W overall output: 4 x 25 W from the subwoofers, 4 x 25 W from the woofers, and 6 x 15 W in the medium/tweeter range. Volume and frequency can be adjusted perfectly for each DSP amplifier channel.

A two-way coaxial system consisting of a subwoofer/woofer and a tweeter loudspeaker is fitted in the lower door area at the front, each of these loudspeakers featuring a top-quality, kevlar-reinforced high-tech membrane. The same loudspeakers are then also fitted on the left- and right-hand side of the rear window shelf, with two woofers installed in double coils beneath the air vent grids in the parcel shelf area.

Measuring 215mm or 8.5" in diameter, these woofers are equipped with a hexacone membrane offering supreme stiffness and low, compact dimensions thanks to its special honeycomb structure. This ensures particularly crisp and natural reproduction of all bass sounds.

Head-Up Display

The Head-Up Display represents an important contribution to enhancing drivers' comfort and all-round safety when travelling. A camera unit within the dashboard projects an in image onto the inner surface of the windscreen where the driver can see it clearly. This image displays information relating to the car's performance, and because it appears to be at the tip of the bonnet, drivers do not need to take their eyes from the road to look at the instrument dials.

The image on the windscreen displays the speed at which the car is travelling; arrows indicating directions supplied by the navigation system, or driver assistants such as Active Cruise Control and the Check/control can be added as well. Measuring some 20 x 10 cm in size, the projection is clearly visible be it sunny or dark, or if a wet road surface is reflecting the headlights of oncoming traffic. The brightness of the image can be varied: your personal setting is stored by the Car/key memory.

Hill Descent Control

A feature in all-wheel driver vehicles, Hill Descent Control (HDC) assists drivers when negotiating a steep downhill route.

It is activated when the automobile exceeds a particular speed when on a descent, and it slows the vehicle down automatically to just over walking speed, while also stabilizing the car and reducing the risk of locking the wheels.

It also gives the driver even greater control over their car without the need to keep the brake pressed constantly. They can vary their speed within certain limits by pressing the brake, accelerator or by using the cruise control buttons. Any drivers behind are warned automatically by the BMW’s brake lights.

Green stripe climate comfort

The climate comfort windscreen uses a layer of infrared-reflecting material to exclude strong sunlight, thus helping to maintain a pleasant cabin temperature.

The green stripe situated at the upper edge of the windscreen prevents the sun from shining directly onto the driver's face, but as it does not impair their field of vision, they still have a perfect view of the traffic in front of them. The windscreen also reduces the surface temperature of the instrument panel should it be subjected to direct sunlight.

Fully-variable intake system

Alongside the valve train system Valvetronic, BMW's eight-cylinder engines possess another innovation that ensures they can adjust perfectly to the driver's power requirements: the fully-variable intake system, DIVA.

It adapts the length of the intake manifold using a coiled regulation mechanism. Long intake travel provides high torque at low engine speeds, short intake travel helps to develop high power at high speeds.

Front-seat adaptive force limiter

Further adding to the occupants' passive safety in BMW automobiles, the front-seat safety belts are fitted with force limiters which judge the strength of an impact and apply the right degree of restraint to protect the occupant.

This prevents injuries caused by the tightness of the safety belt during a collision and ensures that the airbags and safety belts protect passengers more gently as less force is exerted on their heads and chests.

Front and rear side airbags

The side airbags in the front and rear of the car provide two vital functions in the event of a collision from the side. First, they protect the occupant's upper body from injuries caused by outside objects intruding into the vehicle.

Second, they move the occupant's body away from the danger zone, reducing the force exerted on the body during a collision from the side. As a result, a side airbag significantly reduces the risk of injury at chest and hip level.

Four-cylinder engine

The 316ti and 318ti models of new BMW 3 Series compact saw BMW deploy the new generation of four-cylinder engines with their 1.8 and 2 litres of displacement, 85 and 105 kW/6,000 (115 and 143 hp) and torque values of 175 and 200 Nm/3,750 respectively.

Total consumption (combined): from 7.0 to 8.0 ltr/100 km. CO2 emissions combined: from 170 to 194 g/km.

Further information on the official fuel consumption and on the official specific CO2 emissions of new automobiles can be found in the guidelines on fuel consumption and CO2 emissions of new automobiles which are available free of charge at all retail outlets and from DAT Deutsche Automobil Treuhand GmbH, Helmut-Hirth-Str. 1, 73760 Ostfildern-Scharnhausen, Germany.

The defining feature of these engines is their unique Valvetronic valve drive system, a throttle-free regulation mechanism with fully variable valve lifts.

Combined with double-Vanos, this system makes it possible to attain fully variable control of the valve opening times.

Along with this unmatched precision, BMW four-cylinder engines also contain a range of other innovative features such as their four-valve technology, knock control, the plastic intake system and the aluminium crankcase with its open deck construction.

Energy control

Energy control supplies drivers travelling over 20 km/h with constant information about their automobile's current fuel consumption, helping to promote an energy-conscious form of driving. The analog data display is integrated with the tachometer in the instrument panel.

Electronic throttle butterfly control

Replacing the mechanical cable connecting the gas pedal and throttle butterflies, electronic throttle butterfly control works by sending an electrical signal to the engine management with every movement of the accelerator. The system requires a mere 120 milliseconds to open the throttle butterflies in full, about the same time it will take a skilled driver to press down the accelerator.

This allows the driver to apply engine power with greater precision and ensures particularly smooth, vibration-free motoring, above all at low engine speeds. Optimally-timed ignition and valve opening, the ideal throttle butterfly position and volume of injected fuel also serves to optimise consumption and emissions control.

A further important point is that electronic throttle butterfly control enhances driving safety by automatically applying a program in the event of a dangerous mechanical defect, such as the throttle butterflies inadvertently being placed in the full load setting.

Electronic seat adjustment

The seat memory function for the driver seat's electrical adjustment can store up to three individual settings for the seat, settings which include the position of the headrests and angles of the exterior mirrors.

This information is stored electronically and the position of each element can be adjusted at the touch of a button. Some models contain an added option for the position of the driving wheel column.

Electronic immobiliser

The electronic immobiliser secures your car using a chip with an electronic code integrated in the car key. This code consists of a permanent personal code and a second code changed by the immobiliser each time you start the engine.

Whenever the ignition is switched on, the immobiliser first reads the personal code and then asks for the interchanging code. If both answers are accepted, the immobiliser will release the Digital Motor Electronics (DME) with another coded signal, without which the engine cannot be started, not even by short-circuiting it. This data is transmitted through an aerial in the steering wheel lock and is therefore wireless.

The same principle is applied on the key with integral remote control, which is also fitted with a maintenance-free battery which recharges automatically while driving. And should you ever lose your key, you can have it deactivated by your authorised BMW dealer and receive a replacement key without delay.

Electronic brake force distributor

Modern automobiles have relatively large brakes on the rear axle so they can brake over a short distance even if they are carrying a large load.

In order to prevent overbraking when the load is lighter, the electronic brake force distributor constantly monitors the wheel speed of the rear axle and compares this with that of the front axle. If the rear axle threatens to lock, the distributor limits its drive slip: this partial braking re-establishes the car’s directional stability.

Electromechanical Parking Brake

The Electromechanical Parking Brake is an automatic handbrake operated with maximum comfort using a button on the instrument panel. In addition to its primary function when parking, this sophisticated brake system offers two further benefits: Autostop and Hillhold.

Autostop ensures that the car is automatically braked and held at a standstill when required: this means that the driver no longer has to keep their foot on the brake, as is the case on a conventional automatic transmission in order to prevent the usual "idling creep". When setting off, the brake is automatically disengaged once the driver presses down on the accelerator.

Automatically applying the brake and releasing it again, Hillhold prevents the car from rolling downhill when starting on a gradient. With the engine running, all park braking processes are controlled by hydraulics via the Dynamic Stability Control (DSC) pump. When the engine is switched off, the same functions are controlled electromechanically via conventional bowden cables connected to the dual servo parking brake on the rear axle.