Merc unleashes clean-running CL63 AMG

Mercedes recently unveiled its updated CL range and now, barely weeks later, comes the inevitable AMG-tweaked go-faster variants.

The updated CL63 and CL65 AMG models gain the same subtle visual updates (LED daytime running lights plus reprofiled front and rear bumpers) as their lesser siblings, along with the mandatory body kit, quad exhausts and big-wheel/tyre package that adorn offerings massaged by Merc's Affalterbach-based AMG skunkworks.

The range-topping CL65 carries over its twin-turbo V12 powerhouse with 463kW and 1000Nm, but it's a case of all-change as far as the V8-powered CL63 is concerned.

Out goes the free-spinning 6.2-litre (6.3-litre if you work for Mercedes-Benz) naturally-aspirated V8 powerplant used by the superseded model, and in its place resides a clean-burning, direct injection 5.5-litre twin-turbo V8.

In terms of raw numbers the new CL63 AMG certainly moves the game on as outputs of 400kW and 800Nm comfortably eclipse the 6.2-litre motor's quotas of 386kW and 630Nm. What's more, the peak torque figure is at the disposal of your right slipper from as low as 2000rpm.

But just in case you feel the standard 400kW/800Nm engine is a bit weedy, you can opt for an AMG Performance Package that ups the ante to 420kW and 900Nm.

This is all well and good, but what remains to be seen is if the twin-turbo V8 can replicate the stirring soundtrack and crisp throttle response of its 'atmo' forerunner.

Significantly, the new direct-injection powerplant returns a none-too-gluttonous fuel consumption figure of 10.5L/100km, and it emits 244g/km of CO2. Mercedes claims this makes it around 25 per cent more efficient than before.

Merc quotes a 0-100km/h split of 4.5sec for the CL63 AMG, while top speed is electronically limited to 250km/h. However, the AMG Performance Package raises v-max to a supercar-threatening 300km/h.

Both CL AMG models are armed with a raft of driver aids such as active lane keeping assist, active blind-spot assist, night view assist, as well as direct-steer and torque vectoring brake systems -- the latter gently applies the brake on the inner wheel to boost the car's turn-in.

New eco tech includes a stop-start system that kills the ignition at traffic lights and there's a generator management system that uses regenerative braking and engine overrun to charge the battery.

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