This is the most extreme Mercedes SL yet. The SL65 AMG Black Series will offer the same performance as an SLR but is set to cost £100,000 less than the £300,000 supercar.Powered by the SL65's twin turbo V12, the SL Black Series will be subject to a serious weight loss programme and use new turbos to up power to over 650bhp, all of which should see it match the SLR's 0-60mph time of 3.8sec and come very close to its top speed of 206mph. Almost entirely made of carbonfibre, only the doors are standard SL and with the rear wings made from metal the car should weigh around 300kg less than a normal SL65. The SL's folding roof has been replaced by a fixed carbonfibre assembly; removing the electric motors that operate the roof and the folding mechanism helps to save weight. The bespoke body is necessary not only to cut weight but also to cover the car's enormous front and rear tracks. As with all Black Series cars, much of the technology used in this one will find its way into future AMG products; these axles will be fitted to Mercedes' forthcoming SLC supercar that AMG is helping to develop.We'll get our first look at the SL Black Series in July at the German Grand Prix when it will drive out on the track. The car itself will be officially launched at the end of the year.