A new steel driveshaft will take its place.

Starting in November, BMW M3 and M4 buyers will get a bit less carbon fiber in their motoring diet. The automaker is ditching the carbon fiber driveshaft on these models in favor of a new high-performance (and presumably higher weight) steel replacement. And if you can believe it, the reason given by the manufacturer is to help these models meet future emission requirements. Wait, emissions requirements from a driveshaft?

It’s okay, there’s actually a simple explanation though we confess to not fully understanding the logic behind it. 

Hotter M4 coming:

BMW M3-M4 driveshaft

 

According to BMW, the cars will eventually require a petrol particulate filter to meet future statutory emissions requirements in major global markets. Engineers have apparently determined that the filter will need to occupy some of the space currently used by the carbon fiber drive shaft, so a new steel shaft of a slightly smaller size will be installed. It should be noted that the filter won’t be installed; the manufacturer is just making room for it. BMW says the actual filter will come “at a later point in time.”

It’s hard to say whether the switch will have a noticeable affect on feel or performance. The M3 and M4 are certainly rev-happy machines, and that lightweight shaft is part of the equation. For its part, BMW says the new driveshaft will be amazing, ensuring everyone that “the superlative performance and handling qualities of the BMW M3/M4 high performance cars remain unaffected.”

Performance will definitely remain unaffected for M4 CS and GTS models, as they will continue to be offered with the carbon fiber drive shaft. We’re still likely a few years away from an all-new M3/M4, but it’s presumably long enough to force BMW’s hand with a mid-cycle design change.There's no word if the carbon fiber driveshaft might make a return at that point.

It seems a bit confounding to affect such a change for something as basic as a filter, especially when BMW is so proud of its carbon fiber driveshaft. Then again, that’s why we write about cars instead of designing them.

 Source: BMW

Gallery: BMW M3 Competition Package

Hide press releaseShow press release

Technical measure for the BMW M3 Sedan, BMW M4 Coupe and BMW M4 Convertible.

 

Munich. From November 2017 onwards, the CFRP driveshaft in the BMW M3 Sedan, BMW M4 Coupe and BMW M4 Convertible high-performance sports cars (fuel consumption combined: 9.5 – 8.3 l/100 km [29.7 – 34.0 mpg imp], CO2 emissions combined: 218 –194 g/km) will be gradually replaced by an M specific high-performance driveshaft made of steel.

Munich. From November 2017 onwards, the CFRP driveshaft in the BMW M3 Sedan, BMW M4 Coupe and BMW M4 Convertible high-performance sports cars (fuel consumption combined: 9.5 – 8.3 l/100 km [29.7 – 34.0 mpg imp], CO2 emissions combined: 218 –194 g/km) will be gradually replaced by an M specific high-performance driveshaft made of steel. This measure will create the necessary technical basis for meeting future statutory emissions requirements. At a later point in time, a petrol particulate filter (PPF) 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.

For production-related reasons, this pre-enabling needs to be carried out universally for the BMW M3 Sedan, BMW M4 Coupe and BMW M4 Convertible. This measure does not apply to the BMW M4 CS and BMW M4 GTS special-edition models.

Now in their fifth generation, the BMW M3 Sedan, BMW M4 Coupe and BMW M4 Convertible represent the epitome of the high-performance sports car that can be used without compromise every day. Customer deliveries of the successful current generation of models have now topped 68,000.