Mercedes SLK 55 AMG unveiled

The new Mercedes-Benz SLK 55 AMG is the range's most powerful variant ever.

It goes on sale in January and has a 5.5-litre V8 petrol engine that has 61bhp more than its predecessor, yet emits 30% less CO2.

The SLK 55 AMG is the flagship model for the recently launched SLK range. It gets a visual makeover that includes AMG bumpers and grille, dark headlamp lenses, a bootlid spoiler and bespoke alloys. Inside, there are upgraded materials and an AMG steering wheel.

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Mercedes SLK 55 AMG gallery

The 5.5-litre engine is closely related to the turbocharged unit that's used in the E63 AMG, CLS63 AMG, S63 AMG and CL63 AMG. A seven-speed automatic gearbox comes as standard.

A stop-start function helps to make it as efficient as possible. There’s also a ‘cylinder management’ system that can shut down four of the cylinders to save fuel. The system operates from 800- to 3600rpm, if the driver has selected the ‘Controlled Efficiency’ transmission mode. In four-cylinder mode, 170lb ft of the total 398lb ft output is still available.

Upgraded suspension and steering systems give dynamics to match the performance. An optional AMG handling package includes stiffer suspension, rear differential lock and composite front brake discs.

The SLK 55 AMG goes on sale in January 2012. Mercedes hasn’t yet confirmed a price, but we’d expect it to be in the region of £55,000.