DRIVELOGIC shift programs, 11 of them. In this respect, the new transmission parallels BMW M’s 6-speed SMG, offered on M3s since 2002. There are two basic shift modes: Sequential (S), in which most shifting is initiated by the driver; and Automated (D, for Drive), in which operation is similar – but by no means identical – to that of an automatic transmission.

Within these two modes, there are as before a total of 11 shift programs:
• Sequential – 6 programs, S1-S6 from “softest and slowest” to “hardest and quickest” shifts; i.e. from most leisurely to sportiest. The driver initiates shifts with either the console shift lever (tip forward for downshifts, rearward for upshifts) or “paddles” on the steering wheel (left paddle for downshifts, right for upshifts).
• Automated – 5 programs, D1-D5 similarly from mildest to sportiest, with the distinction that as the program gets sportier, the speeds at which shifts occur also move upward. Even in this D mode, if the driver manually initiates a shift, the unit switches to S and remains there until D is again selected by the driver.

In S6, the sportiest program of all, minimum shift time is reduced 20% from the existing SMG – already very fast. In everyday driving, shifts are now smoother.

As in the existing SMG, gears are shifted electrohydraulically; shifting is controlled by a 16-bit microprocessor that can make up to 12 million calculations per second.

Special functions and safeguards. The 7-speed SMG incorporates a number of special functions and safeguards, some familiar and some new:
Automatic downshift to 1st gear for starting off from rest, whether in D or S mode. If the mode selector is in D, upshifts will then occur automatically; or the driver can initiate the upshifts.
Over-rev protection. If the driver calls for a downshift (S mode) that would over-rev the engine, the downshift command is ignored.
Slip Control. If a downshift occurs on a slippery road, SMG disengages the clutch for a split second to prevent sudden wheel slip that could de-stabilize the vehicle.
Start-off Assistant. When stopped facing uphill, the driver simply holds the brake pedal until ready to start off. Upon release of the brakes, the M5 is ready (for 1 second) to start off without rolling back.
Hill Detection. Depending on road gradient, down- or uphill, the D shift points are modified for optimum gear selection. In S, shift times are shortened so that the engine is always “on point” for best acceleration uphill, or engine braking downhill.
Double-clutching. In D or S mode, DRIVELOGIC coordinates clutch disengagement, shifting, engine speed and clutch engagement to accomplish smooth downshifts – just as a skilled driver would.
2nd-gear start in D1 program: Starting up from rest, the transmission is in 2nd rather than 1st; the clutch engages delicately. Although the traction-control function is also there to prevent it, this reduces the chance of even transitory wheelspin.

M5 suspension: targeted modifications
Changes from the regular-production 550i affect the suspension system and its connections to the body structure; a special M version of Electronic Damping Control; the M Variable Differential Lock; Servotronic steering with two levels of power assist; amply dimensioned, cross-drilled brakes; and wheels and tires that give the M5 an awesome footprint.

Start with suspension hardware, already an advanced all-aluminum system on the 5 Series. (The vehicle’s frontal structure too is aluminum, helping contain overall weight and contributing to near-perfect front/rear weight distribution.)

At the front, modifications include the subframe and thrust plate (both still aluminum), fine-tuning of geometry, more rigid bushings and a 0.9-in. wider track. At the rear, the changes are more extensive:
• The subframe is modified.
• Suspension links are essentially the same as in the Z8.
• Bushings are stiffer.
• Axle halfshafts are hollow for reduced weight with greater strength.
• Geometry is tailored to the greater torque that will flow through the whole system.
Here the track is actually narrower (by 0.6 in.) than that of a 5 Series with standard wheels, because the 285/35 rear wheels’ center plane must be farther inboard for their massive tires to clear the bodywork. But the actual footprint is wider.

And at all four wheels, specially calibrated springs and shock absorbers – the latter made variable by Electronic Damping Control – complete a sporting chassis that only BMW M could create.

M Electronic Damping Control
Already offered in the 7 Series but not in U.S. 5 Series or M models, EDC steplessly controls the shock absorbers to any level between softest and firmest, precisely adapting to road conditions and the driver’s demands at any given moment:
• Ride firmness is always optimum for current road conditions, vehicle speed and vehicle loading (passengers and luggage).
• On smooth roads, the shock absorbers are kept at the softest appropriate setting (considering the character of the vehicle) for riding comfort.
• When the vehicle is rounding a sharp corner or curve, the shock absorbers are automatically and instantly adjusted to a firmer, just-right level.
• On any irregular road surface, the shocks automatically and instantly adjust to the optimum level of firmness to control ride motions, preserve riding comfort and maintain adhesion to the road.
• Basic system advantages are calibrated to M Car character.

On the M5, there are three modes rather than the two of the luxury-oriented 7 Series EDC. Selected via the EDC console button or MDrive menu, they are –
• Comfort, shifting the balance toward riding comfort. Appropriate for gentle, speed-controlled driving on relatively smooth and straight roads.
• Normal, likely to be chosen most of the time; a judicious blend of M-style handling precision and riding comfort.
• Sport, putting top priority on the M5’s tremendous road capabilities at some sacrifice of riding comfort.

Within each mode, EDC continuously adjusts shock-absorber firmness to actual conditions. Writing in Automobile Magazine’s November ’04 issue, Georg Kacher concluded that “The new M5…is intuitive and involves the driver every step of the way. It is as stable as its rivals in a straight line, but its steering is lively and soulful. It is as fast through corners, but its handling is sublime and unambiguous. It is as strong on the brake and as energetic on the throttle, but it never forgets to generate feel and feedback.”

M Variable Differential Lock:
putting power to the road, the BMW M way
Mechanical limited-slip differentials belong to BMW M’s tradition of ultimate road handling. Together with the German division of GKN Viscodrive, BMW M engineers developed a more capable mechanical limited-slip differential; called the M Variable Differential Lock, the concept appeared first on the M3, and now comes to the M5.

Under dry to not-quite-dry road conditions, the traditional 25% limited-slip has some ability to improve traction; but under split-traction conditions (one wheel on slippery, the other on firmer ground) it cannot transmit more torque than the slippery side permits. On all current BMW models, electronic traction control (a function of Dynamic Stability Control) addresses this issue, though not optimally for sporty driving in the M Car sense. (Thus there’s a switch to reduce or altogether eliminate DSC action when the driver so desires.)

The M Variable Differential Lock specifically addresses low- and split-traction situations in a way that reinforces sporty handling, imparting a slippery-road ability other high-performance, rear-wheel-drive sports cars generally do not have. The main distinction between a traditional limited-slip “diff” and the M Variable Differential Lock is that where the former senses torque, the latter senses wheel speed.

Anytime a speed (rpm) difference develops between the two rear (driven) wheels, a shear pump, driven by this difference, develops pressure in the unit’s silicon viscous fluid. This pressure is applied to a multi-disc clutch that transfers driving torque to the wheel with the better road grip (this priority is called “select high”). The greater the speed difference between the two wheels, the more aggressively the clutch engages. As this wheel-speed difference diminishes, the clutch begins to ease off.

This mechanism accomplishes finely calibrated action by entirely natural means. There is no external pump, no external source of lubrication or operating fluid. The very motion to be controlled – differences in speed between one wheel and the other – generates its locking action.

Servotronic steering with two effort levels
Like the ’06 7, 6 and 5 Series, the M5’s rack-and-pinion steering system has Servotronic vehicle-speed-sensitive power assist.

Also, the steering ratio – the number of degrees the steering wheel must be turned to steer the front wheels by 1 degree – is variable; the ratio gradually becomes “quicker” (greater steering angle relative to steering-wheel turns) as the steering wheel is turned away from its center position. This is not BMW’s Active Steering, which varies the steering ratio more widely and does so in response to vehicle speed; instead, BMW M chose to tailor the 5 Series’ “standard” steering system to the attributes of this ultimate sports sedan.

But variable ratio and Servotronic assist aren’t all that’s special. For the first time in a production BMW automobile, the M5 offers the driver a choice of two levels of assist: Comfort, with typical BMW assist, and Sport, with less assist for sportier feel. Within these two settings, Servotronic varies the assist according to vehicle speed.

Immensely powerful, fade-resistant compound, cross-drilled brakes
To match its colossal performance, the M5 gets immensely dimensioned ventilated disc brakes. At the front, they are 374 mm/14.7 in. in diameter and 36 mm/1.42 in. thick, compared with the 550i’s already generous 348 x 30 mm. At the rear, they’re 370 mm/14.6 in. in diameter and 24 mm/0.94 in. thick (550i: 345 x 24). But the M5 goes further, with compound brakes.

This most elaborate of BMW brake concepts, also appearing on the M3 with Competition Package, shares 2-piece rotors with the 550i and 6 Series: an aluminum “hat” inner portion to reduce unsprung weight, and a cast-iron outer portion as the actual friction surface). But whereas on those models the hat and outer portion are riveted together, here the hat and outer portion are connected by steel pins on which the aluminum and cast-iron portions, because of their differing expansion rates, can move relative to each other.

The 550i/6 Series’ aluminum/cast-iron rotors cut unsprung weight, and reduce rotor deformation under hard-braking, high-heat conditions by about 20%. This construction is more elaborate and costlier. It saves an equal weight proportion, and totally eliminates deformation. This means virtually no tendency of the brakes to vibrate when red-hot, and virtually no likelihood of the rotors cracking even under the extreme temperatures that might be encountered in driving on a racetrack.

Additionally, the M5 brake rotors – again, as on the M3 Coupe with Competition Package – are cross-drilled to enhance heat dissipation beyond that provided by the rotors’ internal ventilation; this further enhances fade resistance. It also reduces weight – unsprung weight – by a full 1.5 kg/3.3 lb. per rotor. The front calipers have dual pistons, another M5 upgrade; front and rear calipers – highly visible through the wheels – are finished in glossy black.

Thus the M5 incorporates BMW’s most capable braking system. It is one of the many reasons why the M5 is a truly track-ready car.

Wheels and tires: ultimate grip and style
In its wheel-tire equipment, the M5 takes the 5 Series platform to its ultimate level of performance and style. The wheels, in a relatively open, discreetly aggressive M Double Spoke design, are sized 19 x 8.5 front/19 x 9.5 rear and carry 255/40ZR-19 front/ 285/35ZR-19 rear, high-performance tires specially developed for the M5.

These are not run-flat tires; there are no run-flats yet that meet BMW M parameters of speed rating and weight. The M5 exhaust system, with its four main mufflers clustered at the rear of the vehicle, does not provide space for a spare tire, so the M5 is equipped with the M Mobility System.

If a tire is punctured – a rare event in any case – the M Mobility System provides for temporary repair and inflation of the damaged tire. Should a tire ever be completely destroyed, BMW Roadside Assistance is available for the life of the vehicle.

Specially calibrated, variable Dynamic Stability Control
DSC is standard on all BMW models; on M3 models and the M5, this electronic traction and stability system complements the M Variable Differential Lock.

DSC optimizes traction by electronic means. In cooperation with supplier Continental Teves, BMW M engineers have developed specific DSC logic that, together with the fast-responding engine, performance-oriented gearing and differential lock, achieves traction enhancement in an M-compatible way…in other words, without undue interference with M5 performance and the differential lock’s ability to get M power to the road.

The M5’s DSC also includes some new functions recently added to other Series:
• Brake Standby. When the driver lifts off the throttle pedal abruptly, DSC senses that sharp braking may be about to occur and applies just enough pressure to snug up the pads against the rotors. Thus by the time the driver’s foot reaches the brake pedal, the short lag from bringing the pad to the rotor is eliminated; this can reduce the stopping or deceleration distance.
• Brake Drying. Acting on input from the windshield wipers’ rain sensor, the pads are periodically brought up to the rotors – just enough to eliminate any film of water between pads and rotors, but not enough to cause any brake application.

As usual, DSC can be de-activated by the driver. Similarly to the M3 Competition Package, the M5 DSC takes on a unique dimension by offering an M Dynamic Mode. Activated by the DSC console button, this mode allows more oversteer and wheelspin, useful to an expert driver on a race track. It is not recommended for use on public roads.

{mospagebrak title=MDrive: M technology at the driver’s disposal}

MDrive: M technology at the driver’s disposal
Via the MDrive system, the driver has fully 279 combinations of control settings to choose from – and an MDrive button on the steering wheel that allows 1-touch selection of the driver’s preferred combination of same. Here’s how it all works:
Power and throttle response. Three settings: P400, the default mode, allows a maximum of 400 hp and gives “normal” throttle response. P500, the “normal performance” setting, allows full maximum output of 500 hp, with quicker throttle response. Both these settings may be selected conveniently via the Power button on the console, next to the shift lever.
The third setting, P500 Sport, also allows full engine power, but provides even quicker throttle response. It is selectable only in the MDrive menu on iDrive.
Transmission. SMG provides 5 automated programs in Drive, D1-D5; 6 programs in Sequential, S1-S6.
Electronic Damping Control. Comfort, Normal and Sport settings. Steering assist is linked to these: Its Comfort mode (more assist) goes only with EDC’s Comfort setting. The steering’s Sport mode (less assist) goes with EDC’s Normal and Sport.
Dynamic Stability Control. Three settings: Normal, M Dynamic Mode and de-activated (though ABS always remains active).

How does MDrive arrives at those 279 combinations? 3 power settings x 10 SMG programs (excluding for the moment S6) x 3 EDC modes x 3 DSC choices = 270. Then, transmission program S6: Because it can be selected only with DSC deactivated, 3 power settings x 3 EDC modes = 9. Add these to 270 and you get the full 279 modes.

Selecting modes in MDrive. Within the MDrive menu, the driver can select every one of these settings and link them to the MDrive button on the steering wheel. Then, regardless of which individual settings have been selected previously, all these choices are instantly set to what the driver has programmed in MDrive. Conversely, the previous settings will be restored when the MDrive button is pressed again.

Power settings P400 and P500 can be summoned by pressing the appropriate button on the console. So can the EDC and DSC modes; likewise the SMG program, which can be set via the shift lever and the mode selector behind it.

Additional MDrive settings. Two optional features – the M Head-up Display and the M Multi-function Comfort seats’ Active Seat Backrests – can also have their settings programmed onto the MDrive button via the MDrive menu.

Abundant luxury accompanies definitive performance
Imagine the sportiest and most luxurious 5 Series interior. Then imagine it even sportier, more luxurious, and fitted out to enhance enjoyment of BMW M performance. That would be the M5 interior – upholstered in Merino, BMW’s finest leather grade; trimmed in brushed aluminum or a choice of two elegant woods; offering a unique selection of upholstery colors; providing special instrumentation and displays; and offering options such as the M Head-up Display and M Multi-function Comfort seats with Active Backrest Width.

Special M instrumentation
Both main instruments have unique fulltime-illuminated white scales and red pointers. The speedometer scale reads to 200 mph, the tachometer to 9000 rpm. A variable tachometer warning segment in yellow, with red normally beginning at 8250 rpm, is included. Via a rotating disc behind the instrument face, this segment can move downward to as low as 4500 rpm with a cold engine, then gradually rise to the full 8250 rpm as the engine warms. On the speedometer, a similar disc carries a pointer indicating the set speed for the cruise control.

With such a high-performance engine, oil temperature is a critical factor – and the one to which the variable rpm limit is calibrated. Accordingly, an oil-temperature gauge is set into the lower portion of the tachometer. As a further distinction of M5 instrumentation, via the On-board Computer the driver can select oil temperature (instead of average speed) to be shown in the instrument-cluster display.

M sport steering wheel
The M5’s power tilt/telescopically adjustable steering wheel is sized, proportioned and designed to be “as sporty as it gets.” Its distinctions include –
• Smaller diameter: 381 mm/15.0 in. vs. 5 Series’ 385 mm/15.2 in.
• Thicker rim, padded leather with M-color stitching
• Thumb contours at 10 and 2 o’clock
• SMG paddles above lateral spoke: right for upshift, left for downshift
• Round center and unique spoke shape
• MDrive button replaces one of the 5 Series’ programmable buttons.

Merino leather, Extended or Full treatments
BMW’s finest leather grade, Merino, is available in three versions and with unique M colors making up most of the palette.

Standard is an Extended treatment of Merino, appearing not only on the seats and door panels but also the door armrests, center-dash area (surrounding the climate and audio controls), center console and armrest, and handbrake boot. In the optional Full treatment, leather is also applied to the dash. Perforated Merino is available in the Full treatment; it is mandatory with the optional Active Seat Ventilation.

Special interior trim
The standard interior trim – appearing across the dash, on the door pulls and on the center console – is a boldly brushed aluminum. Optional at no extra cost are two elegant woods:
• Olive Carrara Natural, a medium-tone wood with burl grain
• Walnut Madeira, reddish brown with more linear grain.

M sport seats
BMW M sport seats embody comprehensive design and features for supporting the driver in sporting driving.

The standard M front sport seats include adjustable backrest width, which enhances their adaptability to various human statures. Along with the steering wheel and exterior mirrors, each driver’s preferred adjustments are stored in Vehicle & Key Memory and are reset to those adjustments when that driver unlocks the vehicle with his or her remote.

Navigation System and “high” iDrive: standard in M5
This system, optional in 5 Series models, is standard in the M5 and includes –
• GPS Navigation System with DVD database
• High-resolution (640 x 240 pixels), 8.8-in.Control Display
• Controller with Force Feedback (incorporates tactile feedback into controller movements)
• Voice Command of numerous features and functions.

Premium sound: also standard
Optional in the 5 Series, this desirable Package is standard in the M5. It features the acclaimed Logic7 sound system with –
• Increased audio power
• Very high-caliber speakers (aluminum-membrane type for all but subwoofers); 13 speakers, including 2 subwoofers
• Digital Sound Processing (DSP), adjusted along with other Logic7 parameters on iDrive Control Display
• Surround Sound simulation
– plus a 6-disc CD changer, accessed through the glove compartment.

Other features standard in M5
In addition to those already described, the list of further features that are standard in the M5 but optional in some or all 5 Series models is extensive. It includes:
• Xenon Adaptive headlights with auto-leveling
• Headlight cleaning system
• Park Distance Control (ultrasonic parking assist)
• Auto-dimming interior and exterior mirrors
• Ambient Light Package, plus M5-specific entry lights on the doors
• BMW Universal Transceiver (3-function remote control of garage doors, etc.)
• Heated front seats.