Since 1984, four generations of M5s have delighted driving enthusiasts with a combination of breathtaking performance, stunning agility and elegant luxury to create a unique driving experience. The current M5, introduced to the American market in October of 2005, takes those attributes to an even higher level than its predecessors with new design, new technology and new engineering to create what truly can be considered an intriguing combination of a sports car and a luxury sedan.
In its 23/04 issue, the German magazine Auto Zeitung reviewed the latest M5 on the occasion of its European introduction and put it this way:
"The 5.0-liter V-10 would upgrade many super sports cars . . . The power sport seats meet the highest demands for comfort, provide plenty of lateral support and are upholstered in fine leather .
For a nearly 2-ton sedan, it offers outstanding cornering dynamics.
"Yet the fascinating the thing about the M5 is its huge bandwidth of comfort, luxury and dynamics, which other manufacturers can cover only with several model series."
For 2007, BMW M has introduced a 6-speed manual transmission for the M5. This no-cost optional transmission has been developed for and will be offered exclusively in the North American market. It is the perfect enhancement for those driving enthusiasts who want to enjoy the 500-horsepower V-10 engine with the level of driver-car interaction only a manual transmission can offer. Of course, as with any M car, the pedals are arranged to provide smooth and quick heel-and-toe downshifting.
The M5 equipped with the manual transmission features the same M Dynamic Mode (MDM) stability system as the Sequential Manual Gearbox (SMG) car. M Dynamic Mode enables enthusiastic track driving with greater longitudinal and lateral acceleration on dry road surfaces, however, with limited vehicle stability, corrections by the driver may be required. With the M Dynamic Mode activated, stabilizing interventions occur at a reduced level.
Other standard-equipment enhancements include a Tire Pressure Monitor System, a
4-year subscription to BMW Assist (previously 1 year) and a 4-year subscription to
Real Time Traffic Information.
Though based on the current 5 Series Sedans, the M5 is packed with engineering, technology, design and luxury that are all its own. Like all BMW automobiles bearing the "M" logo, it has been developed by BMW M, the BMW subsidiary for high-performance automobiles. The M5 is produced at BMW’s Dingolfing Germany, plant, 60 miles northeast of Munich.
This V-10, designated S85 in BMW parlance, is yet another masterpiece of power from BMW M, setting a new milestone for the performance that can be achieved in a roomy
5-passenger sedan, with generous trunk space and all the luxury and safety features one expects from BMW.
Why 10 cylinders? Elmar Schulte, manager of engine development at BMW, has a straightforward explanation. "We wanted 5 liters. The ideal cylinder displacement is 0.5 liter. To get 5 liters, we needed 10 cylinders."
In its general layout, the M5 and engine relates to, and was inspired by, BMW’s Formula 1 engines the company developed from 2000-2005, also V-10s. In fact, both engines’ major castings are done at the same BMW plant. Although unusual, a V-10 is a satisfactorily balanced configuration, requiring no balance shafts to make it acceptably smooth. Instead, the crankshaft incorporates two large counterweights. Reporting its driving impressions in the December ’04 issue, Road & Track magazine commented: "Run up through the gears out of a slow corner and the engine pulls with a smoothness that easily rivals the [previous] M5’s engine, arguably one of the smoothest V-8s around."
Unique sound is a further attribute of the V-10. Even when idling, it sounds exotic; according to Motor Trend (December ’04). "The yowling twin-five snarl as you sear toward max revs is an experience that etches itself deep in your memory. No, it’s not super-car loud – this car always retains the vestiges of sedan refinement, and you could mount a sustained assault on the Autobahn while the rear-seat passengers sleeps."
High-rpm concept. Like the 6-cylinder M3 engine, the M5’s V-10 was developed to exploit high engine speeds to achieve extraordinary performance. Its redline is 8250 rpm; its maximum power of 500 hp is achieved at 7750 rpm and its maximum torque of 383 lb-ft. is realized at 6100 rpm. This strategy, which avoids extreme torque and instead allows the driver to extract super performance by "revving" the engine, facilitates the use of relatively light, low-mass reciprocating components inside the engine. This helps moderate overall vehicle weight and optimizes the front/rear weight distribution.
Also like the M3 engine, the M5 V-10 does not employ the Valvetronic system now found in BMW’s regular-production V-8 and V-12 engines as well as the N52 and the turbocharged N54 6-cylinder powerplants. Though Valvetronic eliminates the energy-wasting action of throttles, it is not (yet) suitable for high-rpm engines. Instead, the M5 V-10 uses a typical BMW M valvetrain with 4 valves per cylinder actuated by "box-type" hydraulic lifters developed for motorsports. These are small, lightweight and extremely rigid, as they must be to survive an 8250-rpm environment. They are also specially shaped for efficient valve operation, with an oblong cross-section (not round like bucket tappets), slightly curved contact surface and guiding tab to ensure a consistent position in their bores.
The valves themselves are also light, with stems of only 5 mm/0.2 in. And, as on the new six-cylinder engines, the camshafts are hollow, further reducing inertia and enhancing engine response. Altogether, the valvetrain’s reciprocating mass has been reduced 17.5% from the previous M5’s engine; an important facet of the high-rpm concept. So are the light, but ultra-strong pistons and connecting rods.
As in all recent M engines, a special High-Pressure Double VANOS system varies the intake and exhaust valves’ timing steplessly and quickly. As on the M3 engine, the VANOS system has its own hydraulic pump; this contrasts with BMW’s regular-production engines, whose VANOS draws its pressure from the main oil pump. The resulting very high pressure (up to 115 bar/1668 lb/sq in.) enables the valve timing to be varied more quickly than on the regular engines – yet another factor in the high-rpm concept.
Four overhead camshafts actuate the valves. Each of the two intake camshafts, positioned inboard, is driven by a simplex chain; from the camshafts’ chain sprockets, the exhaust camshafts are driven by gears. The system is extremely rigid – again, as it must be for this engine’s level of rotational speed. Each chain is hydraulically tensioned and needs no periodic adjustment or replacement.
Weight-efficient construction. The new M5 engine is of aluminum, with bedplate construction for the lower portion of the cylinder block. This construction is inherently ultra-rigid; for the strength to withstand the massive internal forces of this engine, however, the main-bearing inserts are of cast iron. Sharing a major feature of most current BMW engines – N52 6-cylinder as well as all V-8s and V-12 – the cylinders are silicon-impregnated, with “soft honing” removing just enough of the aluminum to leave the silicon crystals as ultra-hard cylinder surfaces.
The entire engine weighs just 240 kg/529 lb. – almost exactly the same as its V-8 predecessor, yet the V-10 delivers fully 106 hp more output!
G-sensitive lubrication system. Given the 45˚ cant of the cylinder banks and the M5’s cornering ability, special attention has been directed to ensuring natural return of oil to the main sump. There are two sumps, the main and larger one behind the front frame crossmember and a smaller one forward of the member; a baffle separates the two from each other in this “semi-dry-sump” system.
First, the mechanically driven main oil pump is newly of the variable-volume type, an innovation also found on the N52 6-cylinder engine. By varying the output of its pump element according to engine oil pressure, the engineers have achieved a pump that always delivers sufficient pressure to lubricate this demanding engine, yet never pumps more oil than is necessary.
Thus it –
- Contributes to the high power output, by requiring less power from the engine.
- Doesn’t require a bypass to divert excess flow; this helps avoid excess oil temperatures and oil foaming.
There is also a recirculating pump that picks up oil from the small front oil sump and transfers it back to the main sump. Additionally, there is an electrically driven scavenging pump for each cylinder bank. In straight-ahead driving, these pumps pick up oil from the rear of the engine and return it to the sump. In hard cornering (0.6g or greater), the Dynamic Stability Control system’s lateral-g sensor switches magnetic valves to different pickup points in the cylinder heads and the oil pan that are closest to the outside of the curve. This system remains active even if the driver switches off DSC.
The oil level and temperature are monitored by a thermal sensor; a warning is displayed if the level falls low, and an oil-temperature gauge is included in the tachometer face. Oil is cooled by a coolant-oil heat exchanger.
Low-back-pressure, tuned exhaust system. Exiting the engine through stainless-steel exhaust headers that Germany’s auto motor und sport magazine (November 10, ’04) called “an artwork in stainless steel,” exhaust gas from each cylinder travels an ideal length of 560 mm/22 in. before reaching the engine-close first catalytic converter on each side. A high-pressure forming technique is used to shape the headers, enabling them to achieve the necessary strength and desirable light weight with only
0.8-mm/0.03-in. wall thickness. Two additional catalytic converters, one per side, are located farther back in the system.
Further advanced engine electronics. Once again BMW M has developed a new, ultra-powerful electronic control system; called MS S65, this scheme incorporates much of the experience gained from the V-10 racing engine. All the engine’s electronic functions – throttles, ignition, fuel injection, lubrication, dialog with the Sequential Manual Gearbox, and more – are overseen by a central electronic module employing three 32-bit microprocessors capable of 200 million operations per second.
This system also incorporates the MDrive functions, including the three power levels and throttle calibrations described under MDrive.
7-speed Sequential Manual Gearbox
Initially, the M5 is offered exclusively with this unique SMG transmission, which employs Formula 1 racing technology to help drivers extract the M5’s full performance potential. For M5 customers who prefer a conventional manual transmission, a 6-speed will be offered.
The SMG system does everything a manual transmission can do, plus several things a manual can’t:
- Offers 7 forward gears, which would be awkward for a manual shift lever to manage.
- In high-performance driving, can shift much faster than even an expert driver.
- Can provide automated shifting when desired.
- Offers a wide variety of shift programs in Automated and Sequential modes.
- Engages and disengages the twin-disc clutch, precisely coordinating its action with shifts. There is no clutch pedal.
This is the first SMG designed and developed right from the start as an SMG; two BMW M generations and the simpler system offered in regular-production BMWs were created by adding SMG controls to a conventional manual transmission. This has sweeping implications for how the concept operates and what it can do:
- The gears are positioned so that the gearsets with the greatest loads (1st, 2nd and 3rd) are closest to the load-carrying bearings. This promotes durability in a transmission that must transmit immense power and is shifted fast and hard.
- To be shifted by a conventional shift lever, this gearset placement would result in an extremely awkward shift pattern. But this was not a problem, because all shifting would be executed the SMG way.
- Even if the shift pattern were manageable, 7 speeds would be difficult for a driver to manage; a 6-speed is the practical limit for a purely manual transmission.
- And yet with a high-revving, high-performance engine, 7 speeds are ideal and desirable, tangibly helping the driver extract such an engine’s full potential.
- The entire internal mechanism – gears, shafts, bearings, shift rods – could be laid out optimally for SMG’s electrohydraulically powered shifting; it is in no way compromised to allow conventional manual shifting.
- The mechanism allows simultaneous actuation of two shift rods at once, which helps the unit achieve lightning-quick shifts. Additionally, the gear synchronizers utilize carbon-fiber cones, which also contribute to the ability to shift so fast.
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.
Smooth downshifting. 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 slowly. Although the traction-control function is also there to prevent it, this reduces the chance of even transitory wheelspin.
6-speed manual transmission: new for 2007
A 6-speed manual transmission will be available as a no-extra-charge option in model year 2007. As in the previous M5, it is controlled by a handsome shift knob with illuminated 6-speed pattern and M logo. A dual-mass, hydraulically damped flywheel between engine and clutch is specially tuned to the 10-cylinder engine’s power pulses. The primary clutch plate is made of forged steel for high strength. The clutch is self-adjusting, maintaining consistent pedal forces over the life of the clutch; this helped the engineers achieve the necessary high torque capacity with reasonable pedal effort.
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.
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.
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. 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 Leather, BMW’s finest 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 Ash Carrara, a medium-tone wood with burl grain
- Madeira Walnut, reddish brown with more linear grain.
M sport seats
BMW M sport seats embody comprehensive design and features for supporting the driver in enthusiastic 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.