BMW Replaces M3 and M4 Carbon-fiber Driveshafts to Meet Emissions Requirements

BMW has decided to replace the carbon-fiber driveshafts in the BMW M3 and M4 performance models with steel to meet emissions requirements. In the wake of the Volkswagen diesel emissions scandal, emission norms have become a lot more stringent in Europe with countries like UK and France deciding to slowly phase out internal combustion powered cars. Hence, in order to stay emissions-compliant, BMW has decided to add a particulate filter to the exhaust system.

This cannot be done if carbon-fiber driveshafts are used as they have a wider diameter when compared to their steel counterparts, and take up too much space. If steel driveshafts are used instead, there will be no need for a major redesign. In terms of performance, it will not make much difference as the steel component is going to be an M-specific high-performance driveshaft.

It will, however, increase the weight of the car and the engine will need to shift greater mass for the vehicle to move. BMW is likely to offset this by reducing weight elsewhere, possibly by using a lighter flywheel or half-shafts.

The new driveshafts will be used in models produced after November and hence they will be a little less advanced that the M3 and M4 models produced before November.