Mercedes-AMG launches their new A 45/45 S and CLA 45/CLA 45 S with a newly developed 2.0-litre engine. With 387bhp, it stands as the world's most powerful turbocharged four-cylinder engine currently in series production, but those in need of more power still may opt for the S-variants which raise the total power output to 421bhp.

All that power allows the AMG models to accomplish the 0-100km/h sprint in record time - the A 45 S requires only 3.9 seconds, while the basic A 45 model does the same 4.0 seconds. CLA models meanwhile will take an additional 0.1 seconds each. The top speed of the basic models is electronically limited to 250km/h, while the S-models are capable of up to 270km/h.

Power will be put onto the road through the AMG SPEEDSHIFT dual-clutch transmission with eight gears. The active, fully variable AMG Performance 4MATIC+ all-wheel drive distributes the power to the rear axle wheel as necessary for top traction and the spectacular Drift mode. The new rear axle differential now features two multidisc clutches, one for each rear wheel providing greater traction through the bends.

AMG engineers have also extensively reinforced the bodyshell, with a lightweight aluminium plate bolted underneath the engine increasing the torsional rigidity of the vehicle's front end. This is supplemented by a strut tower brace between the front suspension struts and pistol-shaped 'shotguns' that connect the side members to the A-pillars to minimise movements of the front section. Diagonal struts at the front and rear of the underbody also improve rigidity for more precise steering and better feedback.

On the outside the compact now also sports the AMG-specific radiator grille with a wider lower contour and twelve vertical louvres, while bonnet 'powerdomes' hint at the power underneath the bonnet.

The AMG models also get wider front wings with flared wheel arches to create space for the wider front axle. As standard the basic variants will feature 18-inch light alloy wheels in a 10-spoke design, while the S-models are equipped with 19-inch light alloy wheels in a five twin-spoke design. Likewise, basic models will feature grey painted brake callipers with white AMG lettering while the S-versions are recognisable by their larger, red painted six piston brake callipers with black AMG lettering.

Two round twin tailpipes at 82mm in diameter adorn the standard models while S-models are distinguished by their larger, 90mm exhaust tailpipes with internal fluting and AMG lettering.

For those seeking yet more flair, the optional AMG Aerodynamic package includes a modified front splitter and additional gills on the front apron, an additional diffuser blade, side spoiler lips on the rear apron and a rear spoiler for the A 45, or a larger spoiler lip for the CLA 45 in high-gloss black, for optimised aerodynamic balance.

While the AMG Night package finishes design features such as the front splitter and inserts in the side skirts with high gloss black on top of the black chromed exhaust tailpipes.