In 1972, while the rest of the world was absorbed by the Watergate scandal and Mariner 9's beaming back the first close-ups of Mars, BMW Motorsport GmbH was born. In 1978, BMW presented the 2-seat mid-engine M1, whose new twincam 3.5-liter straight-6 would provide the performance foundation for later cars. One example was famously hand-painted by Andy Warhol in 1979, the fourth in a series of the now widely renowned Art Cars, and was raced at Le Mans that year. Again, homologation required M1 road cars to be built, so 445 examples were produced between 1978 and 1981, the engine making 177 bhp in this configuration. On the pure racing side, who could forget Formula 1's 1.5-liter turbo era, with the stock-block M Power BMW in Nelson Piquet's Brabham BT50 making upward of 1200 bhp in qualifying trim. Exciting days, and that Parmalat-sponsored Brabham was one of the prettiest cars of its time, too.
Piquet went on to win the F1 World Drivers Championship in 1983, driving a BMW-powered BT52. Although never seen on U.S. M5’s handbuilt precursor was based on 1979's E12 chassis, the very first 5 Series. In 1993, the motorsports and road-car businesses were separated, and BMW Motorsport GmbH became BMW M GmbH. What follows is a sampling of its M5s over the years. Although exterior changes were rather tame for this first U.S. M5 (The Wolf in Sheep's Clothing, as it came to be known), its engine bay held a derivative of the mighty M1's 3.5-liter twincam 24-valve straight-6. European versions (sold as the M535i) made 286 bhp, but U.S. 256 bhp, enough to keep pace with a Porsche 928 S. It was the first savory taste of the M-calibrated suspension, and our first peek at the iconic row of six individual throttle bodies and competition-look airbox. Worldwide, a total of 2241 cars were delivered, making this M5 a rare bird indeed.
The early 1990s saw a stronger 3535-cc straight-6, now 310 bhp, in the more modern bodyshell. Subtlety in appearance was still BMW's modus operandi, but the M5's odd aluminum/magnesium wheels, whose thick rim flanges gave the tires the appearance of being whitewalls, were aesthetically questionable. Although curb weight had crept to 3950 lb., acceleration was fleet for its day—6.4 seconds to 60 mph and 15 sec. 56,600 base, a considerable fortune two decades ago). Into what many consider the cleanest 5 Series body style ever made was plugged the first M5 V-8 engine, a 4-cam 4941-cc jewel that produced 400 velvety horsepower and revved to 7000 rpm. The individual throttles (now servo-controlled) remained, but hidden in a massive carbon-fiber plenum spanning the cylinder banks. Curb weight still hovered around the 2-ton mark, but the E39 M5's superior power-to-weight ratio enabled a 0-60 Sturm of 5.0 sec. Say what you will about the E60's angry librarian scowl and its unusual trunk cut lines, but this M5's 500-bhp V-10 engine delivered, with a 4.1-sec. 0-60 sprint and a drag strip E.T. 12.4 sec. Oddly, it didn't feel that fast, partly due to soft tip-in torque. The E60 also marked the first M5 not available with a conventional manual transmission; the 7-speed paddle-shift SMG (Sequential Manual Gearbox) was standard, with 11 selectable shift profiles. Purists complained, and BMW did eventually offer the car with a 6-speed manual in the U.S.
With this solution, Mercedes engineers have been able to dispense with the complex actuators and sensor systems used by other variable steering systems. The advantages include very low complexity and weight. The system always responds predictably and consistently while other variable steering systems sometimes require rapid adaptation by the driver in rapidly changing situations. Driving straight ahead in the new SLK also means saving fuel. This is ensured by an ECO steering servo pump as standard in all SLK models. Its centerpiece is an electrically actuated proportional solenoid valve which variably opens a bypass aperture at the pressure connection to feed the steering gear with just the right amount of fluid. As the steering has a lower energy requirement when driving straight ahead, the pressure in the steering system can be minimized and less energy is consumed. The 2012 Mercedes-Benz SLK sets new safety standards in the roadster segment. The safety experts have long adhered to the motto, "The best or nothing", coined by Gottlieb Daimler.
Far from being satisfied with achieving rating targets, they work intensively on attaining a level of safety which far exceeds the standards required by the world's legislators. The most important measure of their work is not the laboratory or crash test facility, but actual, real-life accidents. They call the results of their work Real Life Safety, a concept which is based on research into thousands of accidents. Using this irrefutable evidence, the Mercedes-Benz engineers have developed or initiated most of the assistance systems which today effectively support drivers and have been adopted by many of the company's competitors. The new SLK also features a unique combination of driver assistance systems which help to avoid accidents, including the drowsiness detection system ATTENTION ASSIST. Thanks to this system, the roadster develops a precise feeling for the level of attentiveness of the driver and can provide an early warning of overtiredness. Other standard equipment includes the ADAPTIVE BRAKE which consists of ABS, the acceleration skid control system ASR and also active yaw control (GMR). The optional PARKTRONIC with Parking Guidance supports the driver when parking.
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