Mercedes has lifted the lid on the new SL 65 AMG, the tin-top convertible boulevard cruiser with a supercar-matching 621bhp. See what we did there? It’s like Mercedes has lifted the lid off a box or something, revealing the car, but it also works because you can literally lift the car’s ‘lid’. Which is another way of saying ‘roof’. Amazing.If you’re confused because of a vague recollection of this car having been released already, recently, we can understand why. You’re wrong, but we do understand. The SL 63 AMG was shown not so long ago, at the Geneva Motor Show. This is the SL 65.
That hike from 63 to 65 is a slight one in terms of the tailgate badge, but in reality it is actually hugely significant. The SL 63 AMG has a 5.5-litre V8 with two turbos, producing 537bhp. With an optional Performance Package equipped, it has 564bhp.This car has a 6.0-litre V12, also twin turbocharged, developing a whopping great 621bhp and 737lb ft. That gives it a 0-62mph sprint of four seconds flat, although like most of the other fast Mercs, its top speed is limited to a piffling 155mph.

It’s the same engine as powered the old SL 65 AMG, but revised to benefit economy and emissions as well as performance. Therefore, an engine that did have 603bhp gains 18bhp while using 17% less fuel, now running at a claimed 24.4mpg average.

Not bad at all, plus it’s one of the few modern engines that’s as evocative to look at as it is to hear: it has a carbon fibre and aluminium engine cover…

…well that’s what we hear. Mercedes has mentioned it, but not provided any photographic evidence yet. Instead, here’s a picture of Airscarf, Merc’s nape-warming innovation.

The performance and efficiency gains don’t just come from the engine block – the SL65 AMG is lighter than before, through extensive use of aluminium and carbon composites for the body and chassis, and it uses a seven-speed automatic transmission with start-stop technology, as opposed to the old five-speed unit that did without the fuel saving measure.

Like the smaller SLK, the SL features (as an option) the Magic Sky roof that makes it opaque or transparent at the prod of a button, meaning the sky can be seen and not felt.

The standard kit list is longer and more decadent than Metallica’s rider, including Airscarf, a B&O top end sound system with Frontbass, a tiredness indicator, DVD changer, online functionality and a parking camera.

Autumn 2012 is the planned release date, though the price isn’t confirmed. It will reach into six figures, though.