BMW is developing a new family of modular turbocharged engines, which will be used across the companys entire range of cars, including Minis, from 2014-15.
The engines have been designed around the concept of a single cylinder of about 500cc, which can then be used in multiples of three, four or six for both petrol and diesel engines.
Three-cylinder engines will therefore have a capacity of 1.5 litres, the four-cylinders will be 2.0-litre units and the six-cylinders will be 3.0s. A variety of power outputs will be possible by using single or twin turbochargers.
The engines will be mounted transversely for front-wheel-drive cars and longitudinally in those with rear-drive. The only combination that won't be possible is six cylinders across the engine bay, says Dr Harald Unger, head of the companys in-line engine division.
The petrol units will develop up to 68bhp and 74lb ft of torque per cylinder, while the corresponding figures for the diesels will be 54bhp and 74lb ft.
Unger says the new engine family has been designed to work with electric motors in hybrid cars and can easily be tuned for high-performance models.
This uniform approach to engine design will boost production flexibility and reduce costs, allowing engine factories, such as the one at Hams Hall, Birmingham, to increase output while making savings that can be passed on to buyers.
The major differences between them concern the cylinder heads and combustion processes. There will also be different numbers of internal balancer shafts for smoothness one with three cylinders, two with four cylinders but none with six.
All the engine ancillaries have been moved to the back of the block, making it easier to provide good pedestrian impact protection without having to raise the bonnet line.