The SL65 AMG also takes advantage of a new aluminium bodyshell to help reduce its mass, with the new V12 model hitting the scales 170kg lighter than its predecessor.
Combined with measures such as engine stop-start and the first pairing of Benz's 7g-tronic seven-speed auto with the V12, fuel consumption is improved by 17 per cent - dropping by 2.4 litres to 11.6L/100km.
There's more power, though, of course for the SL65 that goes on sale in Europe in September before reaching Australia in the first quarter of 2013. The 6.0-litre twin-turbocharged V12 engine rises from 450kW to 463kW - beating the 420kW of the SLS AMG supercar - with torque remaining at a still mighty 1000Nm.
Mercedes claims the SL65 AMG will accelerate from 0-100km/h in 4.0 seconds (old model 4.2sec), 200km/h in 11.8 seconds and reach an electronically limited top speed of 250km/h while assuring people that it's kept its distinctive V12 sound.
The new engine is based on the existing motor but is revised for the new SL65 AMG with new turbochargers, new manifolds and a new engine management system bumping up power beneath the carbon-fibre and aluminium engine cover by 13kW.
A newly developed AMG sports exhaust is claimed to yield a reduction in both emissions and weight with the new system 3.2kg lighter than its predecessor.
Further weight saving sees the use of magnesium material behind the tank, carbon-fibre composite for the boot lid inner support, and plenty of aluminium used for steering and suspension components.
The Mercedes-Benz SL65 AMG will come standard with AMG's active suspension (Active Body Control), its newly developed electro-mechanical speed-sensitive sports steering, 3-stage stability control and a thorax airbag located in the backrest that Mercedes says protects the upper body in the event of a side impact.
Standard brakes are 390mm discs with six-piston calipers up front and 360mm discs with a single-piston sliding caliper looking after the rear. High-performance ceramic compound brakes are available as an option as are red-painted calipers and matt black forged light-alloy multi-spoke wheels.
As with the entire SL range, the SL65 AMG comes standard with the electrohydraulically operated vario-roof that will turn roadster to coupe in under 20 seconds with an option for Mercedes' 'Magic Sky Control' roof that can alter its transparency at the touch of a button.
It's too early for Mercedes_Benz Australia to talk pricing for the new SL65 AMG but the old model, priced from $513,760, was even more expensive than the SLS AMG supercar.