New A45 AMG engine in development

The CEO of Mercedes-AMG, Tobias Moers, has confirmed that there will be no more power increases from the world's most powerful hot hatch, the current-generation AMG A 45's engine.

But the new generation engine? That's a different story.

The hot hatch genre has exploded in recent years, with cars like the Audi RS 3 (270kW), Ford Focus RS (257kW) and upcoming Volkswagen Golf R 400 (300kW) pushing the boundaries of what little hatchbacks can do.

The Mercedes-AMG A 45 broke cover in 2013 and is still the most powerful hot hatch today with a 280kW power output after a recent 15kW boost. But the 2.0-litre turbo-petrol engine is at its limit, explained AMG's head honcho during a roundtable interview at the Geneva motor show… And he revealed development of the new engine is well underway – and it could go close to 300kW.

"We should increase power; we should increase torque; we should increase driving dynamics over the [current] A 45. But that's the goal always," he said.

But will it always be the world's most powerful and fastest hot hatch? Moers has previously said it would top 300kW but that may not be enough herbs to claim the title.

"We still have to take care of straight line performance no doubt, but I think to have the package in the right direction is more important than having 10 horsepower more than our competitors," he said.

"We do have comparisons in Germany for A 45 versus the most important competitor [RS 3], and we are by far faster on the racetrack, but sometimes we lose in straight line performance.

"But this is nice in my perspective, this is good, because AMG was formerly known as the straight line performer but not on the racetrack. So we changed the brand 180 degrees."

He confirmed the new engine would still be 2.0-litre displacement, and although he wouldn't say when we'll see it, it could be only a couple of years away from deployment based on the A-Class's current lifecycle.

"Honestly, it's not a big secret, the 381 [ps, German horsepower] is the limit of the engine. In respect of our endurance demands regarding Mercedes engines, that's the very end of that engine [development]," he explained.

As the chase for more power from less continues, Moers defended the need for more torque, suggesting the next engine is unlikely to reach 500Nm. It currently generates 475Nm.

Although the Mercedes-AMG boss recently confirmed he was "excited" about making ferocious hybrid AMG sports cars in future, the new AMG A 45 engine is unlikely to have a hybrid boost system to reach new performance levels.