FIRST DRIVE: Mercedes-Benz SLK55 AMG Black Series.(News)(Product/service evaluation)

Byline: GREG KABLE

The hard-core track-day special comes of age with the new SLK55 AMG Black Series, the first in a range of low-volume AMG performance models aimed as much at the track as the road.

No ordinary SLK55 AMG, the Black Series receives aggressive exterior effects, increased track width and a slightly lowered chassis. The fixed roof is a carbon fiber structure made by ski specialist Fischer in Austria. The single-piece roof trims 176 pounds from the SLK55 AMG's curb weight, although the addition of larger brakes and other changes means overall weight drops just 99 pounds.

At the heart of the two-seater is modified version of the SLK55 AMG's normally aspirated 5.4-liter V8, with an increase in horsepower from 360 to 400.

Turn the key and you immediately notice a harsher exhaust note, with a deep baritone blare from middling revs upward. A lack of sound-deadening floorpan material contributes vibrations and road noise. Throttle response is sharper, and thanks to the various weight-saving measures the power-to-weight ratio is improved, giving the new Mercedes a livelier feel off the line and through the gears.

The standard seven-speed gearbox, with steering wheel-mounted paddles, is reworked with new Speedshift software. It offers full automatic shifting together with two manual modes. Official claims put ...