The Mercedes-Benz SLR McLaren is a German supercar jointly developed by Mercedes-Benz and McLaren Automotive. It is assembled at the McLaren Technology Centre in Woking, England. DaimlerChrysler owns 40% of the McLaren Group.

Though often classified as a supercar, and compared to cars like the Porsche Carrera GT, Lamborghini Murcielago and Ferrari Enzo, the presence of the automatic gear box and its driving characteristics lead some commentators to classify the SLR McLaren as a Super GT whose closer rivals are the Aston Martin Vanquish and Ferrari 599 GTB. One of the goals of the SLR was to combine both supercar and GT characteristics.

It is the fastest automatic transmission car in the world. SLR stands for "sport, leicht, Rennsport" (sport, light, racing). Mercedes-Benz has stated that they will build 3500 SLRs in a span of 7 years, with an annual production of only 500 cars. The car's base price is £300,000 or $ 615,291. (25/07/07 exchange).

History

The Mercedes-Benz SLR McLaren is inspired by the Mercedes-Benz 300 SLR of 1955 which was actually based on the W196 F1 car, yet named after the road-going Mercedes 300SL Gullwing.

Overview

Brakes

The brake discs are carbon-ceramic which provide better stopping power and fade resistance than steel discs. Mercedes-Benz claims these discs are fade resistant to 1000 °C. The front discs are internally vented and 370 mm in diameter. 8 piston calipers are used. Rear discs are 360 mm in diameter with 4 piston calipers. The result of these massive rotors is a maximum braking power of 1500 kW. When it is wet the calipers automatically skim the surface of the disks to keep them dry.

The SLR also has a spoiler mounted on the rear which pops up when braking from high speeds. The spoiler greatly increases drag at high speeds. This additional braking power on the order of 0.25 g of deceleration helps the car to stop quicker than any other car of its category.
 
Engine

The SLR McLaren sports a 232-kilogram (511.8 lb), hand-built, 5.4-litre (5439 cc/331.9 cu in), supercharged, all-aluminum, SOHC V8 engine. The cylinders are angled at 90 degrees with three valves per cylinder and lubricated via a dry sump system. The compression ratio is 8.8:1 and the bore and stroke is 97 milimetre (3.82 in) and 92 milimetre (3.62 in), respectively. The Lysholm-type twin-screw supercharger produces 0.9 bar (13 psi) of boost, the turbine rotates at 23000 revolutions per minute, and the air is cooled via two intercoolers. The engine generates a maximum power of 626 PS (617 hp/460 kW) at 6500 revolutions per minute and a maximum torque of 780 newton-metre (575 lb•ft) at 3250 revolutions per minute.

Unlike most of its contemporaries, its engine is front-mid mounted. McLaren took the original concept car designed by Mercedes and moved the engine 1 metre behind the front bumper, and around 50 cm behind the front axle. They also optimised the design of the centre firewall.

Transmission

The SLR has a five speed automatic transmission with three separate modes: Sport, Comfort and Manual. Sport used for everyday use, Comfort starts in second gear for bumpy or slippery roads. Manual allows the driver to shift gears with the touchpad or the simple levers on the steering wheel. When in Manual, three additional modes (Sport, Supersport, Race) on the second dial can be used, each significantly making quicker shift times. This is the same transmission as used in other performance models such as the SL65 AMG. The Mercedes-Benz seven speed automatic transmission as used on the SLK 55 AMG cannot handle power and torque output of the SLR, S65 AMG, SL65 AMG, CL65 AMG; hence it is fitted with only a five speed transmission.

Performance

Mercedes-Benz's performance claims for the SLR have been confirmed. Depending on the source, the car accelerates from 0 to 100 km/h in approximately 3.5 seconds (see below), 0-200 km/h in 10.6 seconds, and 300 km/h in 28.8 seconds, and has a top speed of 334 km/h (207 mph), and has once reached a speed of 210 mph, which makes it the fastest car with a true automatic transmission with a torque converter. The car uses carbon fibre for its entire body construction, which makes it lighter. However, at 1768 kg, the car is still quite heavy. The SLR is one of the safest and most luxurious supercars ever built, straying from the common supercar practice of eliminating luxuries for the sake of weight reduction.

Car and Driver achieved a 0-60 time of 3.6 seconds, and a quarter-mile time of 11.6 seconds at 125 mph. C&D suggests the times may be even lower if temperatures were higher. Car and Driver achieved top gear acceleration 30-50 mph and 50-70 mph times of 1.7 and 2.4 seconds, which are the fastest ever recorded by the magazine in a production car. The SLR also pulled 0.97 g on the skidpad.

Road and Track tested the car in their July 2005 Road Test and got 60 mph from a standstill in 3.5 seconds. The 0-100 mph sprint was achieved in 7.5 seconds and a Quarter Mile run was completed in 11.5 seconds at 126 mph.

The German magazine Auto Motor und Sport, in 2004, tested the SLR at the Nardo test track in southern Italy. They reported that the SLR accelerates from 0 to 100 km/h in 3.8 seconds, 200 km/h in 10.7 seconds, and 300 km/h in 30.6 seconds. The car's 400-meter time and 1 km time were found to be 11.5 seconds at 207 km/h, and 20.5 seconds at 269 km/h, respectively. They also reached it's claimed 334 km/h topspeed.