2006 BMW M ROADSTER: Taking the Z4 to an Even Higher Level of Performance and Purebred Sport Woodcliff Lake, NJ - January 9, 2006ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¦ At the same time as BMW is launching an updated, newly powered Z4 Roadster Series, the Bavarian automaker is also unveiling a BMW M version of this spirited 2-seater: the M Roadster, which takes the Z4's innate sportiness to an even higher level of thoroughbred performance and driving pleasure. Keen observers of the sports- and performance-car scene will recall that along with the previous generation of BMW's 2-seat Roadster, the Z3, BMW M offered its version. Also known as the M Roadster, it packed M's ultra-high-performance 6-cylinder engine and offered enthusiasts a rip-snortinÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Â¹Ãƒâ€¦Ã¢â‚¬Å“ pleasure machine, long on character and short on timidity. When the current Z4 Roadster was introduced in the 2003 model year, BMW kept a possible M version under consideration. Then, as now, the Z4 Series consisted of two models powered by regular-production BMW 6-cylinder engines. Now, though, the decision is in: Alongside the now improved regular-production Z4s (themselves powered by BMW's new magnesium/aluminum Valvetronic 6-cylinder engine), a new M Roadster makes its debut, with production beginning in January ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Â¹Ãƒâ€¦Ã¢â‚¬Å“06 at BMW's Spartanburg, South Carolina factory. Base price for the new M Roadster is $51,995 including destination. With the M Roadster, BMW brings together the Z4's advanced sports-roadster concept and a version of the BMW M 6-cylinder engine that's even more powerful than that of the previous M Roadster - plus a wide range of new BMW and BMW M developments in suspension, steering, brakes, stability systems, safety features and, not to be left out, luxury and convenience feaures. In short, the new M Roadster is an artful fusion of ultimate BMW M performance, contemporary technology and abundant luxury. The BMW M 6-cylinder engine: thoroughbred performance machine Already known from its application in the award-winning BMW M3 Series, this engine has been aptly characterized as "ferociously powerful" by Car and Driver (May ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Â¹Ãƒâ€¦Ã¢â‚¬Å“03) and "an engine that likes to rev" (Road & Track, December ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Â¦Ãƒâ€šÃ‚Â¡03). The British magazine Engine Technology International has named it Best Engine of the Year for 3.0 to 4.0 liters for five years in a row. Now this remarkable unit gets to power a lighter, even more agile BMW than the M3s. Statistically speaking, the results are dramatic: delivering 330 horsepower at a high-revving 7900 rpm, the internally designated S54  engine propels the 3200-pound Roadster to 60 mph in just 4.9 sec. Maximum speed is electronically limited to 155 mph; speculation about what the top speed might be without the limiter will intrigue enthusiasts, but BMW makes no claim in this regard. As multi-talented as any M Car is - and the M Roadster certainly is that - its heart is always the engine. Under the M's aluminum hood with its distinctive added contour lines is an engine like none other. In its broad concept, this engine shares its inline format with other BMW 6-cylinder engines. Virtually all its engineering details, however, are unique and targeted to the very highest level of performance. Unlike other 3 Series engines, which employ lighter materials for their block and cylinder head, the S54 combines a cast-iron block with its aluminum head; this was adopted to achieve the engine's 3.2-liter displacement without lengthening the block. The block accommodates this engine's bore and stroke of 87.0 x 91.0 mm, both larger than the dimensions of BMW's 3-liter engines. However, playing larger roles than increased displacement in the 75-hp increase over the most powerful regular-production 6-cylinder engine is the M3's induction, combustion and exhaust engineering, together with its execution as a high-rpm engine. The starring role here is played by a cylinder head that could be termed "exotic." Its key features include: Double VANOS  steplessly variable valve timing on the intake and exhaust camshafts. Though this system appears in all other current BMW engines, in the M unit it varies timing over a wider range and contributes in a major way to the engine's ultra-high power output. VANOS pressure pump. In regular-production BMW engines the main oil pump supplies the pressure to operate VANOS; here the VANOS system has its own radial-piston hydraulic pump. Integral to the exhaust camshaft's VANOS mechanism, the pump produces up to 120 bar (1740 lb./sq in.) of pressure to vary valve timing more quickly at the very high rpm this engine reaches. BMW M refers to its VANOS system as High-Pressure Double VANOS; it is also used in the M5's 500-hp V-10 engine. Unique valve mechanism. All BMW engines have an efficient valve mechanism. Yet for an engine with the S54's rpm potential, BMW M engineers needed less reciprocating mass than in the regular-production engines. To achieve this, they created a unique actuating mechanism, using extra-light finger-type rocker arms. Pivoting on their own shafts (one on the intake side, one on the exhaust), these small arms provide the actuating surface between camshaft and valve. As the entire arm does not move the distance of valve lift, its effective reciprocating mass is less than its actual mass. All told, the valvetrain's effective mass is 30% less than in the BMW 6-cylinder engines that have bucket-type hydraulic lifters; in turn, this allows lighter valve springs, which further reduce inertia. The system also has less friction. As there is no hydraulic maintenance of valve clearance, it does have to be inspected periodically. It is unlikely that clearance will ever require adjustment, but if so it is done with shims (tiny metal discs of various thickness) without removing the camshafts. Whereas the "regular" 6-cylinder engines have simplex (single) camshaft drive chain or chains, the S54 has a full duplex (double) chain driving its camshafts. As usual with BMW engines, the chain is hydraulically tensioned and needs no periodic adjustment or replacement. Extra-high compression ratio. At 11.5:1, the M engine has the next-highest ratio in current BMW production, topped only by the new M5ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Â¹Ãƒâ€¦Ã¢â‚¬Å“s 12.0:1. Machined surfaces. More "engineering finery" again: Combustion chambers and intake ports are completely machined, for smoothness that facilitates airflow. The exhaust ports are partially machined. For durability, the valve seats are of especially hard steel. A 3-layer stainless-steel head gasket ensures effective sealing of the head to the block. Head casting and sealing. Extreme strength in the cylinder head is achieved by making it a single aluminum casting. Though elaborate, this construction also saves a significant 29 lb. As this weight reduction is at the top of the engine, it helps lower the car's center of gravity. Induction system: BMW M tradition, state-of-the-art technology The S54 engine manifests an important BMW M tradition: an individual throttle for each cylinder. Positioned much nearer to the cylinders than a single throttle can be, these bring atmospheric pressure practically right to the cylinder. The "lag time" inherent in airflow into the cylinders is thus greatly reduced and the engine can react more quickly to throttle movements. Via the accelerator pedal and its two potentiometers, the driver gives the commands, in turn processed by the engine control module and received by a DC servo motor. The motor drives the throttle shaft through a tiny gearbox. Upstream of the throttle bodies are the six intake trumpets, made of weight-efficient fiberglass-reinforced PA6 thermoplastic; these are laser-welded into the induction plenum of the same material to form a single assembly. M Dynamic Driving Control provides Normal and Sport settings for throttle response. In Sport, selected via a console switch, the ratio of throttle opening to pedal movement is increased so that apparent engine response is even quicker. Even the transitional response of the electronic engine controls is altered to suit. Drivers tend to find one or the other setting more to their liking, or choose them according to driving conditions or mood. The system always defaults to Normal when the engine is started. Together with VANOS, this elaborate induction system adds to the engine's immense breathing and fuel/air processing capabilities. Exhaust system: engineered for free flow For the M Roadster, it was necessary to develop a newly routed exhaust system because its underbody is quite different from that of the M3s that the S54 engine also powers. As in the M3s, after the partially machined exhaust ports, the system begins with two snaking stainless-steel headers serving three cylinders each. These elaborate headers are "hydroformed" under high pressure with liquid inside them, which ensures even distribution of the forming pressure and thus consistent wall thickness. In turn, this process allows stainless-steel walls only 1 mm thick (about 1/25th of an inch), not only helping save weight but also hastening engine warmup as there is less metal to heat up after a cold start. Each header is a single piece, thus not welded-up as are most headers. For effective emission control during engine warmup, the forward catalytic converters are right at the headers. From these catalytic converters rearward, the dual exhaust system continues through mufflers, resonators, two additional catalysts and finally four chrome outlets that speak the authoritative tones of M Power. The more constricted space available under the Z4 body costs 3 hp compared to the M3; but then the Roadster weighs 218 lb. less than the M3 Coupe, more than offsetting the slight reduction in power. In its sound quality, the M Roadster exhaust system is tuned for a somewhat milder tone than that of the M3. High-performance lubrication and cooling To help ensure adequate lubrication under the high cornering, acceleration and braking loads the M Roadster attains, the S54 engine employs a "semi-dry-sump" oiling system. Particularly in hard cornering to the left, it is critical to ensure return of oil to the pan; therefore, integrated into the gear-type pressure pump is a scavenging pump that collects oil from the right side of the small forward oil sump and pumps it back into the main, larger rear sump. This rear sump is almost completely closed off from the rest of the system, and thus able to hold the oil necessary for lubrication throughout the engine. Specific return passages are also incorporated into the intake (left) side of the engine to help ensure ideal oil flow under all operating conditions. The graphite-coated aluminum pistons are cooled by oil spray; each valveÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Â¹Ãƒâ€¦Ã¢â‚¬Å“s rocker arm is sprayed with oil just before it is loaded by its camshaft lobe. A thermal sender monitors oil level and temperature. If the level drops low, a warning appears in the instrument cluster; the tachometer face includes the oil-temperature gauge. The cylinder head incorporates crossflow cooling; this promotes consistent temperatures from the front to the rear of the head, helping minimize distortion and wear under the extreme heat such a high-performance engine develops when its full power is being exploited. The high-rpm concept High engine speeds are essential to achieving high power from moderate displacement, but they pose challenges; engineers must ensure that durability standards are met at these levels. The S54 engine's maximum power occurs just below its 8000-rpm limit at 7900 rpm. To achieve this revving capability, the engineers applied a number of detail measures. A forged, nitro-carbonized steel crankshaft provides great strength in this critical component. Forged-steel "crack" connecting rods eliminate the need for bolt sleeves and thus reduce reciprocating weight. A unique water pump plays a role too. The crossflow cooling requires high coolant flow. To achieve this, the engineers developed a pump with 3-dimensionally contoured vanes. Such contours would have been inordinately costly to produce in metal, so BMW M developed a novel pump design. Each vane is a small plastic casting, pressed into an also-plastic rotor and then welded into place. Also adding cooling efficiency is a ring thermostat, which imposes less resistance to coolant flow than a conventional plate thermostat. Electronics play their role too. The engine's control module - newly developed for the M Roadster application - calculates and adjusts the ignition and fuel injection at each cylinder individually every 6 degrees of crankshaft rotation, it. Ignition occurs through a very small-diameter "pencil" coil at each cylinder. Spectacular results: power, torque, revs, performance, sound At this writing, no published road tests of the new M Roadster are available for quotes; but there has been plenty of praise for the same engine in the heavier M3 models. In a March '03 comparison test, for example, Road & Track reported that "the M3's engine possesses an uncannily smooth power delivery. Not only smooth, but also flexible, the M3's six has a wide, usable powerband. Midrange punch is already good, but once above 4000 rpm, the engine adopts an even more menacing snarl as it pulls strongly right up to the redline." Great looks too: the view under the hood Following a long BMW M tradition of visually attractive machinery, the S54 engine's appearance is as beautiful as its engineering. Tubing - for the idle air supply, fuel to the injectors, fuel from the fuel pump - is stainless steel. Housed in cast aluminum, the VANOS mechanism projects prominently forward of the cylinder head. Stainless-steel screws secure the camshaft cover; chrome rings hold the induction trumpets to the ports. The "M" logo and a special M oil filler cap adorn the front of the camshaft cover. M Roadster drivetrain: getting S54 power to the road Like every M Car to date, the M Roadster transmits its power to the road via classic rear-wheel drive  and includes some premium and fascinating engineering into its drivetrain. 6-speed manual transmission. Like the M3s, the Roadster comes with a 6-speed manual transmission. Making its first appearance in an M Car is the ZF Type H, which features evolutionary improvements: ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Even more effective synchronization of shifts ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Lighter and more pleasing feel as shift lever is moved from gear to gear ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Firmer engagement of gear once selected ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Shorter "throws" from neutral to each gear ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Use of lifetime transmission oil, which never needs to be changed ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ "Clean bearings" design for main transmission bearings; protects bearings from contamination, ensures adequate lubrication at all times and therefore enhances durability. As in other M models, the shift pattern on the gearshift knob is illuminated attractively at night. No alternate transmissions are offered. Super-sized differential unit. A specific subframe allows equipping the Roadster with the same heavy-duty differential dimensions as in the M3s. A special high-strength steel alloy is used for the differential gears to achieve quietness and durability. As at the front spoiler, rear diffusor and elsewhere along the underbody, airflow under the vehicle is carefully managed and targeted; here, a ribbed differential case and NACA air intakes for the differential unit help keep the oil cool. M Variable Differential Lock. Together with the German division of GKN Viscodrive, BMW M engineers developed a special mechanical limited-slip differential that made its first appearance in the M3s and now also appears in the M5. This M Variable Differential Lock specifically addresses low- and split-traction situations in a way that reinforces sporty handling while contributing to remarkable slippery-road abilities. Any time a speed difference develops between the two rear (driven) wheels, a shear pump, driven solely by this difference, develops pressure in the silicon viscous fluid in which the lock operates. In turn, this pressure is directed to a multi-disc clutch that transfers driving torque to the wheel with the better road grip ("select high"). The greater the speed difference between the two wheels, the more aggressively the clutch engages. As soon as the difference between the two wheels' speeds begins to diminish, the clutch starts to ease off. This mechanism achieves its sophisticated 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 left and right wheels - generates its locking action. Viscous fluid is so-called because it develops internal force (via an increase in viscosity) whenever it is sheared; this is why the relatively small difference between one wheel speed and the other can generate the necessary action. Dynamic Stability Control. This electronic traction and stability system, standard on all current BMWs, complements the M Variable Differential Lock. DSC optimizes traction by electronic means, sensing wheel-speed differences and reducing engine torque and/or applying individual rear-wheel brakes. The crucial difference to the M Roadster driver between the M Variable Differential Lock and the DSC traction function is that the former in no way impedes power delivery, and is hence suitable for performance driving. Yet in fact, even DSC's traction function is calibrated to M-specific parameters. In combination with the fast-reacting engine, performance-oriented gearing and M Variable Differential Lock, its logic achieves the desired traction optimization in an M-compatible wayÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¦in other words, without undue interference with the differential lock's ability to get power to the road. The DSC stability-enhancing function is essentially unrelated to traction. Sensing differences in wheel speed in a critical cornering or avoidance maneuver, DSC detects any deviation from the normal cornering path (abnormal understeer or oversteer) and gently applies individual wheel brakes to help the driver keep the vehicle on the intended path. As in other recently introduced BMW models, the M Roadster's DSC system incorprates new functions: ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Brake Drying. Acting on input from the windshield wipersÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Â¹Ãƒâ€¦Ã¢â‚¬Å“ rain sensor, the brake pads are periodically brought up to the rotors - just enough to eliminate any film of water between the pads and rotors, but not enough to cause any brake applications. This improves brake readiness in wet driving conditions. ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Start-off Assistant. Keeps the vehicle from rolling backward when stopped facing uphill. For 2 seconds after the brake pedal is released, the driver can then move off from rest without the car rolling back. ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Modulated ABS function. Thanks to new "analogized" control of the DSC brake valves, the anti-lockup function (ABS) is smoother than before. Instead of simply being fully applied and released, the application and release of these valves is now modulated. New DSC braking functions found in regular-production models, such as Comfort Stop, are not included in the M Roadster because of its ultra-sporty driving character. Subscribe to the Motor Portal! Click on the link above and submit to receive updates Click here for financing The M Roadster chassis: extensive new engineering by BMW M Starting with the Z4's already excellent chassis engineering - Motor Trend commented in its May ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Â¹Ãƒâ€¦Ã¢â‚¬Å“05 issue that the Z4ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Â¹Ãƒâ€¦Ã¢â‚¬Å“s "sport suspension and solid chassis make this car a thrill to drive on canyon roads" - BMW M has endowed the M Roadster with typical M modifications that further enhance handling and tailor the car's road capabilities to M's higher performance level. New front suspension. While retaining the Z4's basic concept - strut-type with forged-aluminum lower arms - the M engineers created an essentially new version with: ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ A wider front track (by 0.5 in.) ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Newly configured lower arms, still of forged aluminum; more complex shape with open sections for lightness, similar to those of M3s ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ New steering knuckles, bolted to the struts (saves weight, sharpens steering response) Such changes, subtle yet deep-reaching, are - as good as the basic BMW model is - key to achieving the "beyond exceptional" reflexes of an M model. Rear suspension. Though modifications to the Z4's Central Link (multi-link) rear suspension are less extensive than at the front, they are significant. Among others, the following major M elements are shared with M3s: ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Rear subframe - larger and stronger; accommodates differential with M Variable Differential Lock ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Wheel bearings ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Central (longitudinal) Links ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Arrangement of anti-roll bar. As at the front, these modifications sharpen handling capabilities. Ride height and suspension calibration. Like the Z4's sport suspension, that of the M Roadster is set lower compared to the standard Z4's setup. Unlike the Z4, however, the M gets an all-around new calibration of springs, shock absorbers, anti-roll bars and bushings to BMW M parameters; this includes specific auxiliary springs at the front and rear. A new steering system. Alone among BMWs, Z4s have electrically assisted power steering. With this system's vehicle-speed-sensitive power assist, it is notable for its combination of reduced driver effort in parking and at low vehicle speeds, and good road feel at higher driving speeds. BMW M has somewhat different priorities: a greater emphasis on absolutely accurate road feedback and ultra-spontaneous response to the driver's commands at the steering wheel. In this context, higher parking and low-speed efforts are acceptable. Thus M gave the Roadster what is essentially the M3 steering system, with - ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ The hydraulically assisted rack and pinion of the M3s ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ A power-steering pump similar to that of M3s, but with newly calibrated assist characteristics As with M3s and other BMW models that have engine-speed-sensitive power assist, this system reduces parking efforts somewhat, but not to the degree that vehicle-speed-sensitive assist does. Interacting with the M front suspension, this Roadster steering system helps deliver the sort of reflexes that a Road & Track editor commented upon in December '03: "The M3 isÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¦the sharpest tool for carving up a back road." BMW M's most advanced brake system. The M Roadster comes standard with BMW M's most elaborate brake concept, one that is part of the M3's Competition Package and is standard on the M5: compound, cross-drilled 4-wheel ventilated discs. The brake rotors are 2-piece, with an aluminum "hat" and a cast-iron outer portion that is the actual friction surface. 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. This is an elaborate, costly construction that cuts unsprung weight and eliminates rotor deformation under hard-braking, high-heat conditions. In practical terms, this means virtually no tendency of the brakes to vibrate when hot, and also virtually no likelihood of the rotors cracking under the extreme heat conditions that might be encountered in driving on a race track. Dimensions are as on the M3 with Competition Package. At the front, the discs are of 345-mm diameter x 28-mm thickness (13.7 x 1.10 in.); at the rear, the discs measure 328 x 20 mm (12.9 x 0.79 in.). Cross-drilling, visible through the wheels, enhances heat dissipation beyond that provided by the rotors' internal ventilation, further increasing the brakes' resistance to fade, improving braking effectiveness in wet weather and reducing unsprung weight. Given the Roadster's lighter weight compared to the M3s, these brakes can be expected to achieve even more phenomenal retardation. Wheels and tires: ultimate style and grip. Except for wheel design, M Roadster wheel and tire equipment is the same as that of M3s. M Double Spoke wheels, with a very open configuration to help get plenty of cooling air to the brakes, complement the Roadster's body with a boldly sporty, yet elegant design. Sized 18 x 8.0 front and 18 x 9.0 rear, they are connected to the road by suitably wide, low-profile, high-speed-rated tires sized 225/45ZR-18 front / 255/40ZR-18 rear . As with other BMW M models, the Roadster's tires are not run-fats; run-flat tires that meet M requirements are not yet available, and their extra weight detracts from the extreme handling characteristics BMW M specifies. Also, the M exhaust system's bulk precludes a spare tire. Thus like other BMW M models, the Roadster comes standard with the M Mobility System for use in case of a flat tire. M Mobility consists of a container of rapid sealant, a small compressor, and a hose to connect the compressor to the damaged tire. All this is carried in a container in the trunk; the system can seal punctures up to approximately 1/4 inch across. Omitting the spare tire saves about 45 lb. of weight. The Roadster's wheels incorporate the so-called Extended Hump rim shape, which helps keep the tire on the rim in case of deflation. Tire Pressure Monitoring. Another element of the Roadster's tire/wheel equipment is its new, standard Tire Pressure Monitoring system. Of the two types of tire-pressure measurement currently in use, this is the more elaborate: Pressure in each individual tire is measured directly and monitored via telemetry. If pressure in any tire drops below a defined level, this is indicated by a warning in the instrument cluster. At 32 psi, recommended tire pressure for the Roadster is relatively low to achieve maximum grip in spirited driving. Optimum weight distribution. Like all BMWs, the M Roadster is laid out for relatively even front/rear weight distribution: 50.7% front/49.3% rear. The M Roadster look: subtle and purposeful The transformation from a regular-production BMW model to a BMW M creation is always subtle, always purposeful. The M Roadster is clearly in this tradition. At the front, there is a complete new fascia - bumper, spoiler, grille framing - that makes a statement both esthetic and functional. The traditional BMW "kidney" grilles are set deeper into their openings. Their vertical slats are black, harmonizing with the three black-trimmed air-intake openings underneath. To satisfy the engine's and brakes' cooling requirements, these are somewhat larger than the new Z4's single opening. Standard Xenon headlights with auto-leveling include BMW's popular luminous rings on the inboard lamps, functioning as parking lights but also remaining illuminated when the headlights are on. A high-intensity headlight cleaning system is also standard. As on Z4s, the hood is aluminum, positively influencing weight distribution and overall vehicle weight; it includes two longitudinal "precision lines" not present on Z4s. At the sides, the 18-in. M Double Spoke wheels and their ultra-low-profile performance tires reflect the Roadster's performance priorities, while an M logo just behind the characteristic Z4 diagonal slash and its BMW logo-cum-turn indicator confirms the Roadster's heritage. In its rear view, the Roadster also has its own bumper ensemble; this includes a diffusor and cutouts for the four chrome exhaust tips. As on '06 Z4s, the taillights are new, and feature upper sections with three horizontal LED strips; these sections serve the second stage of illumination provided by BMW's Adaptive Brake Lights under hard braking. The M logo appears again here, on the left side of the trunklid. BMW M has developed an attractive spoiler that adds emphasis to the trunklid's distinctive arc-shaped upper lip; this is offered as an option (as of April '06 production) for the M Roadster. Also M-specific are three M exterior colors: Imola Red and the metallic Interlagos Blue and (to be phased in beginning with April '06 production) Sepang Bronze. Softtop and interior: M also means luxury The M Roadster embodies the best of Z4 luxury and then some. Standard, for example, is the fully automatic softtop, which comes in a choice of three colors and includes an interior lining for enhanced weather protection. The rear window is glass, and includes heating. Like the Z4, the M Roadster has a variable storage compartment for the softtop, which allows greater trunk space when the top is up; however, compared to the Z4 Roadster, the M's trunk has about 3/4 of a cubic foot less volume because its battery and the M Mobility System are carried within the trunk space. Doorsill trims display the M logo (with its three colors) in a large, handsome format. Once inside the M cockpit, the driver and passenger enjoy a uniquely sporty, high-quality atmosphere blending BMW M's style of abundant luxury with typical BMW functional design. Premium Nappa leather M sport seats (choice of manual or power) include embossed M logos on the head restraints. Leather also appears on the door panels, console armpad, kneepads, handbrake grip and shift knob. Trim materials are special: The largest areas (across the dash, center console) are in a sporty-technical Aluminum Hexagon surface, while pearl-gloss galvanic trim appears on the climate controls, interior door handles and pulls, and the "tubes" into which the main instruments are recessed. Automatic climate control is standard in the M, and its rotary knobs also include the new rubber touch surfaces that enhance their tactile feel. Tactile feel is also a strong point of the M sport steering wheel, which displays its heritage with an M logo on the bottom spoke and M-color stitching of its thick leather rim. Fingertip audio controls and tilt/telescopic adjustment are included on the wheel. As in other M models, instrumentation is special, both optically and functionally. The instrument cluster reflect the M's performance capabilities with special features: ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ 9000-rpm tachometer scale ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Variable tachometer warning segment that lowers the redline according to engine temperature: lowest with a cold engine, then increasing in increments to an 8000-rpm limit with a fully warmed-up engine. Although this feature appears in some regular-production BMW models, the BMW M graphics (with an arc of orange and red LEDs) are different. ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Oil-temperature gauge at bottom of tachometer dial ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ 180-mph/300 km/h speedometer scale ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Distinctive graphics throughout, including red-on-gray dial pointers. Two alternate trim materials are offered in place of the standard Aluminum Hexagon: Carbon Leather at no extra cost, and the elegant Walnut Madeira wood (that's also offered in the M5) at extra cost. Also available is even more luxurious Full Leather upholstery; see options for details on this and other available features. An extensive complement of safety engineering and features Every current BMW incorporates from-the-wheels-up engineering and technology for active safety - the kind that helps drivers avoid accidents - and passive safety - features that help protect the occupants should an accident happen. The M Roadster's handling and braking capabilities, described earlier, are the active side; occupant-protection features include the following and more: ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Dual front-impact Smart Airbags ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Automatic safety-belt tensioners and force limiters ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Seat-occupation detection on passenger's seat ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ LATCH attachment of child-restraint safety seat to passenger's seat ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Side-impact airbags ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Rollover Protection ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Battery Safety Terminal ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Intelligent Safety & Information System for deployment of safety devices and systems. Options The M Roadster's level of standard equipment is generally higher than that of the top Z4 (3.0si) model, but it does offer an interesting array of options: Premium Package. Combines luxury and convenience features, plus BMW Assist, BMW's system of customer services and in-car telematics. The Package includes: ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Auto-dimming interior and exterior mirrors ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ 8-way power sport seats with driver's-seat memory (the thigh-support adjustment remains manual) ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Cruise control ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Premium audio system with - ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Upgraded speakers throughout, including two 160-mm subwoofers that incorporate Carver long-stroke technology ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ A powerful Carver amplifier and 7-band Digital Sound Processing ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Storage package - elastic net on right side of center console and back of each seat. ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ BMW Assist. Metallic paint. Initially, the M Roadster metallics include Interlagos Blue (an M color), Titanium Silver, Black Sapphire and Silver Gray; another M color, Sepang Bronze, will be added later. M rear spoiler. Described earlier. BMW On-board Navigation System with DVD database. As in Z4s, the system's display is housed in a pop-up pod at dash center; in addition to GPS Navigation, On-board Computer and other functions, it also assumes the role of audio-system display. When the radio is switched on, the Navigation monitor automatically rises into its operating position. With the premium audio system (Premium Package), the Digital Sound Processing function is controlled from the Navigation display as well. Extended Leather upholstery. Although the standard interior (described earlier) is quite luxurious, BMW M offers additional luxury and distinction via this option. Available in Black and Sepang Bronze, it adds leather coverage in many areas: ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Complete door panels; standard coverage is a portion of the doors ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Windshield frame ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Sun visors ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Center console ÃƒÆ’Ã†â€™Ãƒâ€šÃ‚Â¢ÃƒÆ’Ã‚Â¢ÃƒÂ¢Ã¢â€šÂ¬Ã…Â¡Ãƒâ€šÃ‚Â¬ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â¢ Rollover bars. Alternate interior trim. Choice of Carbon Leather at no extra cost or Walnut Madeira wood at extra cost across the instrument panel and on the center console. Power seats with driver's-seat memory. In addition to being part of the Premium Package, the 8-way power seats are available as a stand-alone option. Heated seats. 3-stage, thermostatically controlled heating provides a wide range of adjustability and steady heat under changing temperature conditions. Hardtop preparation. Factory preparation for hardtop installation is a factory option; the hardtop itself is available as an accessory from the BMW center. BMW Assist: for added peace of mind Available as part of the Premium Package or as a stand-alone option. In-vehicle equipment for BMW Assist includes GPS technology plus an Assist button on the center console. Vehicle occupants may request emergency or other services simply by pressing the button; the BMW Assist system transmits vehicle location and information to the BMW Assist Response Center. A response specialist then contacts the occupants to coordinate dispatch, notify emergency contacts on file if required, and link BMW Roadside Assistance or emergency services as needed and requested. Deployment of an airbag automatically activates BMW Assist as well. A year's subscription to the BMW Assist Safety Plan is included with the option; after the initial year, the annual fee is $240. In addition to the safety-related benefits, subscribers to the Convenience Plan (available for an additional $120 per year) can call a toll-free 800 number to avail of many BMW Assist Concierge services, from travel planning to dining reservations, shopping assistance and event tickets. Like all current models, the M Roadster is covered by BMW's 4-year/50,000-mile limited warranty and 12-year/unlimited-mileage corrosion coverage, and continues to come standard with a 4-year/50,000-mile Full Maintenance Program for customer convenience, peace of mind and economic benefit. Performance with a conscience BMW strives to produce its motor vehicles and other products with the utmost attention to environmental compatibility and protection. Integrated into the design and development of BMW automobiles are such criteria as resource efficiency and emission control in production; environmentally responsible selection of materials; recyclability during production and within the vehicle; elimination of CFCs and hazardous materials in production; and continuing research into environmentally friendly automotive power sources. Tangible results of these efforts include the recycling of bumper cladding into other vehicle components; water-based paint color coats and powder clear coats; near-future availability of hydrogen-powered models; and various design and engineering elements that help make BMWs easier to dismantle at the end of their service life. BMW Group In America BMW of North America, LLC has been present in the United States since 1975. ROLLS-ROYCE Motor Cars NA, LLC began distributing vehicles in 2003. The BMW Group in the United States has grown to include marketing, sales, and financial service organizations for the BMW brand, the MINI brand, and the ROLLS-ROYCE brand of Motor Cars; DesignworksUSA, an industrial design firm in California; a technology office in Silicon Valley and various other operations throughout the country. BMW Manufacturing Co., LLC in South Carolina is part of BMW Group's global manufacturing network and is the exclusive manufacturing plant for all Z4 Roadster and X5 Sports Activity Vehicles. The BMW Group sales organization is represented in the U.S. through networks of 340 BMW passenger-car centers, 327 BMW Sports Activity Vehicle centers, 148 BMW motorcycle retailers, 80 MINI passenger-car dealers, and 25 ROLLS-ROYCE Motor Car dealers. BMW (US) Holding Corp., the BMW Group's sales headquarters for North, Central and South America, is located in Woodcliff Lake, New Jersey. Information about BMW Group products is available to consumers via the Internet at: www.bmwgroupna.com www.bmwusa.com www.bmwmotorradusa.com www.miniusa.com www.rolls-roycemotorcars.com  - BMW M engines are designated "S" for Sport. Current regular-production 3 Series BMW 6-cylinders are of the M54 (Coupes and Convertibles) or N52 family (Sedans and Sports Wagon).  - VANOS = VAriable NOckenwellen Steuerung = variable camshaft control, or variable valve timing.  - The original M Car, the M1, had a midship engine and rear-wheel drive.  - Due to low-profile tires, please note: wheels, tires and suspension parts are more susceptible to road hazard and consequential damages. The Z4 M models are not equipped with a spare tire and wheel. Performance tires are not recommended for driving in snow and ice conditions.