Engine downsizing is not a trend, but purely a way to offer more fuel efficient engines that also comply with tougher emission standards. All this is possible thanks to recent technologies with smaller turbo engines providing the power of a larger engine.

New BMW M3 and M4 have been out for a short time and the biggest update with the arrival of the new M sedan and coupe was the new six cylinder twin-turbo engine, replacing the outgoing naturally aspirated engine. Two cylinders less, but still delivering 425 horsepower vs 414bhp in the outgoing model.

It is interesting to point out that the first M3 was powered by a 192bhp 2.3-litre inline-four, with the next one using six and then the outgoing one already eight cylinders.

Looks like BMW is heading back to its roots as the next-generation M3 and M4 could use a turbocharged four-cylinder engine.

BMW M product manager Carsten Pries told Motoring.com.au in a recent media launch in Portugal that the future [M3 and M4] could be powered by a four-cylinder engine.

The output has always risen in the M3 so we can only expect the next-gen model will pack more than 425bhp than in the current model. Over 425bhp from a four-cylinder engine is not impossible, but with current production engines it would make it the most powerful four-cylinder turbo in the world.

For example the production version of the VW Golf R 400 concept is reported to produce over 395bhp from a 2.0 litre turbo, so if VW can do it in a hatch, then we are sure BMW can pull it off with their M cars.