Mercedes has released images and details of the its long-awaited performance flagship for the latest A-Class range, the AMG-tweaked A45.

However, don't let the A45 badge fool you into thinking this baby Merc is powered by a massive throbbing V8. Instead, confusingly it has got this name as part of the celebrations in the run up to AMG's 50th birthday in 2017.

What the A45 does have under its bonnet is the most powerful four-cylinder engine in the world. Also the first four-cylinder engine ever fitted in an AMG model, the 2.0-litre turbocharged unit boasts a massive 335bhp and 332lb-ft of torque.

This engine is mated to seven-speed automatic transmission with three modes, plus standard 4MATIC four-wheel drive that should make it easier to get all of this power on to the road.

Top speed is electronically governed to 155mph, whilst acceleration to 60mph takes just 4.6 seconds. Yet it's still capable of returning over 30mpg and produces just 161g/km of Co2.

Each example of the all-aluminium engine is hand built at AMG's Affalterbach plant by a single technician – good for a boast or two down the pub.

Outside, you'll be able to spot the A45 by its deep front splitter and AMG-specific grille finished in matt grey. Elsewhere, there are gloss black painted air intakes, sill skirts, door mirrors and it rides on 18-inch alloy wheels to cover the bigger brakes.

Inside, there are new AMG high-backed seats, a revised instrument cluster, plus red highlights for the air vents and seat belts.

The A45 will make its debut at the Geneva Motor Show next month and will be available in the UK from July.