BMW has announced a "technical measure" for its M3 sedan, M4 coupé and M4 convertible that will see the carbon-fibre-reinforced plastic (CFRP) driveshaft on these models replaced by a steel version.

The reason for the switch from what the automaker earlier described as a "fundamentally new approach" to the manufacturing of this component? To "create the necessary technical basis for meeting future statutory emissions requirements".

In short, this means that the CFRP driveshaft, which by design features a larger diameter than the steel version, will apparently prevent the fitment of new emissions control devices that the Munich-based brand will soon have to install in its vehicles.

Interestingly, the switch will not apply to the M4 CS and M4 GTS special-edition variants.

The change to an "M-specific high-performance driveshaft made of steel" will take place from November 2017, BMW said in a statement, adding that "at a later point in time, a petrol particulate filter will be incorporated into the existing installation space in these models in major markets".

"The newly developed steel driveshaft has been designed to ensure the superlative performance and handling qualities of the BMW M3/M4 high-performance sports cars remain unaffected," the statement added.

But will drivers notice a difference? Well, while that seems unlikely, there probably will be a minimal weight addition, considering that at the launch of these models, BMW said the use of the CFRP component resulted in "a weight saving of 40 percent" (as well as "a reduction in rotating masses")...