Mercedes-Benz SL65 packs whallop

Mercedes is bursting into the luxury roadster ring with its half-million dollar slammer.

The 463kW/1000Nm 6-litre V12 SL65 comes hot on the heels of the V8-engined SL63 and the SL500, earlier tested for the first time by Carsguide in Spain.

The Mercedes-AMG SL65 takes on convertibles such as the Porsche Turbo S Cabriolet ($442,800); Audi R8 V10 ($380,200); Jaguar XKR-S ($364,000); Ferrari California ($459,650); and Lamborghini Gallardo ($515,000). 

Mercedes Australia spokesman Jerry Stamoulis says though the new SL will make it's Australian debut in September, the first SL65 AMG vehicles won't get here until early 2013.

"Pricing will be announced in September, but you can expect similar pricing to the outgoing model,'' he says.

PRICE

The existing SL65 is $513,760. Mercedes-AMG says the roadster blends the exclusivity of V12 dynamic performance with the luxury and refinement of a saloon.

"We have developed an incomparably exciting high-performance vehicle for the small but loyal community of fans,'' says the company's CEO, Ola Kallenius.

WEIGHT AND THIRST

Like the SL500, the V12-engined AMG version has an all-aluminium body that trims weight down to 1950kg - about 170kg less than the previous model.

Fuel thirst is claimed to be 11.6 litres/100km, down 2.7 l/100km (or 17 per cent on the outgoing SL65) thanks to the weight reduction and the seven-speed automatic gearbox's wide-spaced ratios and the stop-start system.

PERFORMANCE

The improved fuel economy hasn't comes at the detriment of performance. The bi-turbo engine has 463kW (up from 450kW previously) and 1000Nm of torque for a 0-100km/h sprint time of 4.0 seconds.

It gets to 200km/h in 11.8 seconds, less time than many cars get to 100km/h. Mercedes-AMG says the engine is based on the previous model but has been revised with new turbochargers, new manifolds and a new exhaust system. This exhaust is 3.2kg lighter than the old model.

TECHNOLOGY

The gearbox can be switched through four modes from "controlled efficiency'' to "sport'', "sport-plus'' and "manual''. The transmission also automatically blips the throttle during downshifts and provides some theatre ``through the brief, precisely-defined interruption of ignition and fuel injection during upshifts under full load''. 

Standard equipment includes the ABC active suspension system with two ride choices - sport and comfort - and AMG-developed electro-mechanical steering. The brakes are steel rotors but the SLS's ceramic discs are on the option list. Options also include the "magic sky control'' glass roof that can be switched from light to dark at the push of a button. 

The "airscarf'' neck heated air system, active park assist, Bang & Olufsen audio, "Comand'' online communication, power door closers and automatic, pop-up roll-over bars are standard.