Powered by a naturally-aspirated version of AMG's new 5.5 litre V8, the SLK 55 AMG belts out 310kW and 540Nm of torque and is capable of rocketing from zero to 100km/h in just 4.6 seconds.
Top speed is electronically limited to 250km/h.
The SLK 55 AMG is priced at $155,000 before on-road costs ($24,360 less than its predecessor), and will also be offered with the optional AMG Handling Package.
Priced at $8825, the AMG Handling package includes carbon-ceramic front brake rotors, a firmer AMG Performance suspension and a locking rear differential to improve traction under power.
For a sports car with a 5.5 litre V8, the SLK 55 AMG's fuel economy is actually quite decent thanks to Benz's cylinder deactivation technology. Claimed fuel economy on the combined cycle is only 8.5 litres, with average CO2 emissions of 163g/km.
The SLK 250 BlueEfficiency also joins the SLK range, and sits between the already-established SLK 200 and SLK 350.
With a starting price of $91,900, the SLK 250 is $9325 less expensive than the car it replaces - the 2011 SLK 300 - and $640 cheaper than the previous-gen SLK 200 manual.
Powered by the same basic 1.8 litre four-cylinder engine as the entry-level SLK 200, the addition of more turbocharger boost sees power and torque rise to 150kW and 310Nm.
The SLK 250 is only available with a seven-speed automatic transmission, with paddle shifters as standard to enable manual control of gearshifts. Performance is appreciably brisk, with a 6.6 second 0-100km/h sprint time.
Fuel economy is quite good too, with the SLK 250 BlueEfficiency sipping just 7.0 litres of premium unleaded on the combined cycle.
As standard, the SLK 250 is equipped with power-adjustable seats and steering column (with memory settings for both), heated mirrors, self-levelling bi-xenon headlamps, 17-inch alloy wheels and an internet-enabled onboard telematics system.
2012 Mercedes-Benz SLK 200 BlueEfficiency: $82,900
2012 Mercedes-Benz SLK 250 BlueEfficiency: $91,900
2012 Mercedes-Benz SLK 350 BlueEfficiency: $118,900
2012 Mercedes-Benz SLK 55 AMG: $155,000
2012 Mercedes-Benz SLK 55 AMG With AMG Handling Package: $163,825