| New Range Flagship | 2008 Geneva Motor Show | Mercedes-Benz SL 63 & 65 AMG |

The facelifted Mercedes SL goes on sale in the UK in April and there will an all-new SL 63 AMG model to replace the SL 55 that has been a sales hit for Merc. To improve on the 55, AMG has shoehorned its 6.2-litre V8 under the bonnet to equip the luxury roadster with 525bhp.

This is enough power to see the SL 63 accelerate from 0-62mph in 4.6 seconds and charge on to an electronically governed top speed of 155mph; though Merc insiders say that the car is good for more than 190mph if the limiter were removed. The new engine does away with the SL55's supercharger and also does without the turbos fitted to the V12-engined SL 65.

A new seven-speed automatic gearbox comes with the SL 63, which has four different settings to suit the driver's moods. There's the choice of Comfort, Sport, Sport+ and Manual, and the engine's ECU brain now blips the throttle on downshifts to smooth progress and keep the car more stable during hard driving.

As well as the various settings for the gearbox, it now has a 'Race Start' function that provides perfect getaways by balancing acceleration with available grip through the ESP system. The driver selects the Race Start programme, holds the car by the foot brake with his or her left foot and presses the throttle flat to the floor. The gearbox then does all the clever work to give maximum acceleration.

The ESP has been updated for the new AMG versions of the SL. It now has three modes, covering On, Off and Sport, with Sport allowing a controlled amount of wheel spin before the traction and stability controls kick in. The revised ESP works in conjunction with the SL's Active Body Control and lets the driver tune the car to their preferences.

Both the SL 63 and SL 65 have the same facelifted front end as the rest of the SL range, and they also get Merc's 'AirScarf' system that blows warm air through the seats' headrests to keep passengers snug when driving with the roof down in cold weather.

Other new features for the revised AMG SLs are 19-inch alloy wheels, a black-painted grille with larger air intakes beneath it and air vents in the side of the front bumper to let hot air escape from the oil cooler. There are also unique side skirts, a rear apron with diffuser, boot spoiler and four chromed exhaust pipes.

Inside, there's an AMG steering wheel, sports seats with leather upholstery and a new dash that includes a 'Racetimer' function to let the driver record lap times on track days.

Prices for the SL 63 and SL 65 models will be announced at the same time as the other revised SL models nearer to the cars going on sale in the UK in April.

Alisdair Suttie - 8 Feb 2008