The Citroen DS is an executive car produced by the French manufacturer Citroen between 1955 and 1975. Styled by Italian sculptor and industrial designer Flaminio Bertoni, the DS is known for its aerodynamic futuristic body design and innovative technology, including a hydropneumatic self-levelling suspension. The DS advanced achievable standards in automobile ride quality, handling, and braking.[2] Citroen sold nearly 1.5 million D-series during the model's 20-year production run. The DS came in third in the 1999 Car of the Century competition, recognizing the world's most influential auto designs, and was named the most beautiful car of all time by Classic & Sports Car magazine. After 18 years of development in secret as the successor to the venerable Traction Avant, the DS 19 was introduced on 5 October 1955 at the Paris Motor Show. The car's appearance and innovative engineering captured the imagination of the public and the automobile industry almost overnight. In the first 15 minutes of the show 743 orders were taken, and orders for the first day totalled 12,000.[4] Far from being just a fascinating technology in search of a purpose, contemporary journalists were effusive in noting how the DS dramatically pushed the envelope in the ride vs. handling compromise possible in a motor vehicle. To a France still deep in reconstruction after the devastation of World War II, and also building its identity in the post-colonial world, the DS motor car was a symbol of French ingenuity.[citation needed] It defied virtually every automotive design convention of that era. It also posited the nation's relevance in the Space Age, during the global race for technology of the Cold War.[original research?] Structuralist philosopher Roland Barthes, in an essay about the car, said that it looked as if it had "fallen from the sky". Outside of France, the car's radical and cosmopolitan design appealed to non-conformists. An American advertisement summarised this selling point: "It takes a special person to drive a special car".[citation needed] The DS was historically significant for many reasons, one being that it was the first mass production car with front power disc brakes. It also featured hydropneumatic suspension including an automatic levelling system and variable ground clearance, power steering and a semi-automatic transmission, and a fibreglass roof which reduced weight transfer.[citation needed] Inboard front brakes (as well as independent suspension) reduced unsprung weight. Different front and rear track widths and tyre sizes reduced the understeer typical of front-engined and front-wheel drive cars. In conventional cars, hydraulics are only used in brakes and power steering. In the DS they were also used for the suspension, clutch and transmission, although the later ID19 did have manual steering and a simplified power braking system. At a time when few passenger vehicles had independent suspension on all wheels, the application of the hydraulic system to the car's suspension system to provide a self-levelling system was an innovative move. This suspension allowed the car to achieve sharp handling combined with very high ride quality, frequently compared to a "magic carpet". The system used – hydropneumatic suspension – was pioneered the year before, on the rear of another car from Citroen, the top of range Traction Avant 15CV-H. In a hydropneumatic suspension system, each wheel is connected, not to a spring, but to a hydraulic suspension unit consisting of a sphere of about 12 cm in diameter containing pressurised nitrogen, a cylinder containing hydraulic fluid screwed to the suspension sphere, a piston inside the cylinder connected by levers to the suspension itself, and a damper valve between the piston and the sphere. A membrane in the sphere prevented the nitrogen from escaping. The motion of the wheels translated to a motion of the piston, which acted on the oil in the nitrogen cushion and provided the spring effect. The damper valve took place of the shock absorber in conventional suspensions. The hydraulic cylinder was fed with hydraulic fluid from the main pressure reservoir via a height corrector, a valve controlled by the mid-position of the anti-roll bar connected to the axle. If the suspension was too low, the height corrector introduced high-pressure fluid; if it was too high, it released fluid back to the fluid reservoir. In this manner a constant ride height was maintained. A control in the cabin allowed the driver to select one of five heights: normal riding height, two slightly higher riding heights for poor terrain, and two extreme positions for changing wheels. [The correct term oleopneumatic (oil-air) has never gained widespread use. Hydropneumatic (water-air) continues to be preferred overwhelmingly.] The DS did not have a jack for lifting the car off the ground. Instead, the hydraulic system enabled wheel changes with the aid of a simple adjustable stand

Koenigsegg Automotive AB is a Swedish manufacturer of high-performance sports cars based in Angelholm. The company was founded in 1994 in Sweden by Christian von Koenigsegg, with the intention of producing a world-class supercar. Many years of development and prototyping led to the company's first street-legal production car delivery in 2002. Norwegian designer and entrepreneur Bard Eker bought a 45 percent share in the company in late 2005, and is currently the largest owner with 49 percent. Christian von Koenigsegg owns 18 percent, and the balance of the stock is held by some 90 small investors. The Koenigsegg CCX is a mid-engined roadster from Swedish car manufacturer Koenigsegg. The CCX has been engineered to comply with the U.S. regulation and market demands[2] and is a newer design that replaced the Koenigsegg CCR. CCX is an abbreviation for Competition Coupe X; the X commemorating the 10th anniversary, (being the Roman numeral for ten), of the completion and test drive of the first CC vehicle in 1996. The CCX was first unveiled on February 28, 2006 at the 2006 Geneva Motor Show although its existence was announced earlier. A derivative known as the CCXR is available, the main difference being that CCXR's engine is tuned to run on biofuel. The different fuel and tune allows the CCXR to produce 25% more power than the CCX. Koenigsegg began the CCX project with the aim of entering the world market, though particularly the United States car market.[6][7] Development engineer Magnus Jaasund said "We wanted to go into the world market, but we couldn’t do it with the old car." To sell cars to the North American market many alterations were made to the design of the CCR; the previously used Ford Modular engine was replaced by a Koenigsegg engine designed to run on 91 octane fuel, readily available in the United States, and to meet the Californian emission standards.[6][8] The front bumper of the CCX is designed to be safer in low speed collisions than previous Koenigseggs and the whole body is 3.46 in (88 millimeters) longer to comply with the United States' rear impact regulations. Additionally the CCX can display United States or European number plates. The CCX is 1.6 in (40.6 mm) taller than the CCR and, combined with the carbon fiber reinforced plastic sports seats by Sparco, the CCX allows for 2 in (50.8 mm) of extra headroom that Autoweek reviewer Mark Vaughn hypothesizes is "to accommodate U.S. NBA stars.” The electronic control unit has also received an upgrade over the CCR meaning that the CCX is without physical fuses and it is lighter than the previous system. The CCX can accelerate from 0–62 mph (100 km/h) in 3.2 seconds and from 0–124 mph (200 km/h) in 9.8 seconds. According to Koenigsegg it has a top speed of 259 mph (417 km/h), although this has not been officially verified. On 15 June 2008, a standard fully equipped CCX was independently timed by sport auto in achieving a record 0-186-0 mph (0-300–0 km/h) in 29.2 seconds, beating out the Mercedes-Benz McLaren SLR 722 Edition, the Lamborghini Murcielago LP640, the Porsche 997 GT2, the Alpina B6 S (based on the BMW 6 Series), and the Corvette Z06. The engine of the CCX was thoroughly re-engineered by Koenigsegg themselves and is assembled at the Koenigsegg factory, though it is still based on the Ford Modular architecture. [12][13] The engine block is cast for them by Grainger & Worrall, a British company that produces drivetrain components for Formula One cars. The engine is a 4.7 liter 288 cu in (4,719 cc) V8, with dual overhead camshafts and 4 valves per cylinder. The engine block is made of 356 Aluminium that has undergone a T7 heat treatment, a form of accelerated precipitation strengthening.[8][16] The aluminium alloy is stronger than the previous engine and allows a thinner, thus lighter, engine block that will withstand higher cylinder pressures. The engine is boosted by two centrifugal superchargers that provide 17.5 psi (1.2 bar) of boost with an 8.2:1 compression ratio. The engine produces 806 bhp (601 kW; 817 PS) at 6900 rpm and 678 lb·ft (919 N·m) of torque at 5700 rpm on 91 octane (U.S. rating) gasoline. The engine is lubricated with a dry sump system with a separate oil pump, the pistons are cooled by oil sprayed onto them and the oil itself has an external cooler. The CCX does 14 mpg (17 l/100km) in combined cycle and 18 mpg (13 l/100km) in highway travel. In 2007, the CCX was the fastest car to complete a lap of the BBC Top Gear circuit, in a time of 1:17.6 on the Power Lap, until it was beaten by the Ascari A10 with a time of 1:17.3. The car originally lapped the circuit in 1:20.4, but was then fitted with a non-standard rear spoiler to provide downforce after the show's test driver (The Stig) spun the original version off the track. The Stig purportedly recommended this modification, predicting that the car would then be the fastest ever round Top Gear's track but Koenigsegg later stated that the improv