[CanAutM3]

The CS also have recalibrated ABS and DSC systems to better take advantage of R-comp tires. The ABS programming is a further development of the GTS one. AM&S found in their testing the CS stops in a significantly shorter distance than the GTS. I personally found the MDM of the CS to be significantly better than even the EU MDM I had coded on my previous M4.

You are right in saying the impact of the changes to the CS are significant, making the CS a much better track car. The whole car was tuned to better take advantage of sticky R-comp tires. I was 2.5 sec/lap faster with my CS than I was with my 2015 M4 at my local track (~1:50 lap), and that is on the same wheels and tires (APEX EC7 shod with NT01). That is a massive difference. Heck, I beat my previous best lap by 2 seconds on the first day I had my M4cs on track. Those changes also made the M4cs feel much more connected and dynamic at more sedate daily driving speeds, significantly enhancing the driving experience. I daily drove the CS on the star spec PSC2, which I find made the car whole and more cohesive.

Regarding suspension, there is a difference between the M4cs and M3cs, where the M4cs uses the Competition pack springs while the M3cs uses the bases spring, making the M4cs more stiffly sprung than the M3cs. Not quite sure why BMW did that though.

The M4cs also had a hybrid sound system with less speakers that shaved a few more lbs and still sounded fairly decent.

The single zone HVAC system shaves a fair bit of weight from the reduced ducting and dampers. And as a tidbit about the rear HVAC, while the center console vents are removed, there is still is HVAC an fed to the rear compartment footwell from under the front seats.

The hood serves 3 purposes: front downforce, reduced weight and improved cooling.

For my part, I really appreciated the center armrest removal and reduced door armrest for the increased elbow room it provided when driving on track. I really realized it when I took a student’s M3CP out for a few laps that almost felt claustrophobic in comparison.

As another tidbit, Melbourne red was only introduced for 2020MY replacing black in the standard M4cs colour palette. IMO, LRG is the colour to have because it is the only exclusive colour to the CS. SMB was made a standard colour (replacing SS2) and FDB was made available as an “Individual” option on the base M4 for 2020MY.

The M3/4cs were often misunderstood. They were clearly not intended for everyone. But for those that they appeal to, it is one fantastic car. It is by far the best ///M car I’ve ever owned.