Secrets of BMW's next M3

BMW'S next-generation M3 cult car will return to its spiritual inline six-cylinder roots - albeit with a pair of turbochargers - when it makes its global debut in 2014.

BMW Group Australia spokesman Piers Scott suggests to Drive that the fifth-generation M3 halo car - like the forthcoming M5 saloon - will trade a pair of engine cylinders for turbos. It also follows the Bavarian brand's shift towards an entirely turbocharged line-up across the model range.

The fifth-generation M3 will be powered by a 3.0-litre twin-turbo inline six-cylinder engine that's believed to develop around 335kW of power from lower revs than today's model. Also expect a higher torque figure that's available almost off idle for greater flexibility and fuel efficiency.

By contrast, the current car is powered by a naturally aspirated 4.0-litre V8 engine that develops 309kW of power at a high 8300rpm and 400Nm of torque from 3900rpm.

Following the original (E30) M3's high-revving 2.3-litre four-cylinder engine, subsequent generations used a naturally aspirated six-cylinder unit, measuring 3.0-litres and later 3.2-litres in capacity - all of which were high-revving and up to 254kW in power.

Adding to the next M3's higher engine output, BMW is also likely to focus on reducing the current car's 1580-kilogram weight via a greater use of lightweight carbon fibre-reinforced plastics (CFRP) - as seen on the current M3 Coupe's roof - for improvements to fuel economy, handling and performance. This should also result in a 0-100km/h sprint time better than the current car's 4.6 seconds.

Customers will have the choice between a conventional six-speed manual or a seven-speed 'M' dual-clutch automated gearbox.

Last year BMW announced a joint venture with carbon-fibre producer SGL Group to invest $US100 million in a CFRP manufacturing plant in Washington, US.

The more aggressively styled M3 is believed to take inspiration from the CS and Vision EfficientDynamics concepts and will again be offered in volume-selling Coupe as well as Convertible variants.

With BMW confirming the introduction of a 3-Series Gran Turismo — a larger five-door hatch-cum-coupe similar to the 5-Series Gran Turismo — an M3-GT version is believed to be under consideration instead of a regular four-door sedan that typically rivals the Mercedes-Benz C63 AMG, Audi RS4 and Lexus IS-F.

Rather than being based off the 3-Series Touring platform, the 3-GT may be built from the larger 5-Series, similar to the 5-GT's 7-Series underpinnings, says Scott. Either way, BMW will offer only one style of four-door M3, he says.