Mercedes-Benz SLK 55 AMG

The headlines include a naturally aspirated 5.5-litre V8 engine that's tuned to produce 416bhp and 398lb ft of torque, and capable of hurling the SLK from 0-60mph in just 4.6 seconds.

It delivers a relentless shove of acceleration and an increasingly intense exhaust note as you barrel up the road.

Perhaps even more startling, though, is the fact that it will also return 33.6mpg. To put that in perspective, it's a 30% improvement on the outgoing car.

Some of this gain is down to the fitment of a stop-start system and subtle efficiency tweaks, but it’s mainly thanks to cylinder shut-off technology. Under light engine loads – between 800rpm and 3600 – four of the eight cylinders can be switched off, dramatically reducing fuel consumption.

We haven’t been overly impressed with the latest SLK’s handling, which is all a bit on the stodgy side, but this AMG version shows what can be achieved with a little tinkering.

AMG sports suspension, beefier stabiliser bars, a bespoke steering rack and a system that employs the rear brakes to force the nose of the car to turn in aggressively all have a positive influence on the car's agility. Together, these mods also provide much higher levels of driver feedback.