It doesn’t matter what this hardcore M4 will be called, because it’s going to hit hard when it arrives next year
BMW has been testing various M4 mules with some subtle aero and chassis upgrades for a while now, but things just got serious with this prototype that could signal the return of the CSL nameplate.
Unlike previous prototypes which looked to feature little more than some tacked-on body upgrades, this one has a more substantial set of changes including a return to placeholder lighting units and an application of new bodywork for the bumper, bonnet and front wings. Intriguingly, BMW has also fitted a new grille insert with a cutout that looks plenty wide enough to fit an extra character on the badge that’ll inevitably adorn it.
Looking closely at the bonnet you’ll note that while there’s no obvious opening, it does have some cleverly blended cladding hiding what will almost definitely be a bespoke carbonfibre bonnet.
At the rear is a new boot lid with an M3 CSL-like moulded ducktail that’s completely different to the standard M4 spoiler. Again, using BMW’s lesser CS models as reference, they’ve generally featured a stick-on carbon lip over the top of a standard bootlid rather than an entirely new unit as seen on here, suggesting another bespoke carbonfibre component.
The car also features a deeper front splitter, capped at either end with low-mounted flicks, and a unique wheel design hiding the gold brake calipers usually associated with BMW’s carbon ceramic brake package. This prototype is also running very serious Michelin Cup 2 R rubber, again signalling this is running hardware that’s a level up on comparative CS models.
Any upgrades to the engine are typically impossible to spot from prototype cars like this, but the M4’s closed-deck S58 3-litre turbocharged straight-six is ripe for further modification despite its already strong 375kW peak output. The question of whether a future M4 CS or CSL will retain rear-wheel drive or pick up the Competition’s optional all-wheel drive is also one we’re looking forward to being answered. There is one sneaky powertrain detail we can spot though, and that’s the typical blue-hue of a titanium alloy being used on the visible exhaust box.
Whatever this mule ends up as, those in the market for an even more dynamic iteration of the M4 won’t have to wait long as BMW plans on revealing this hardcore model next year. With the standard Competition having made an excellent first impression, the foundations are already in place for an even hotter version to be something truly special, and we can’t wait to see what comes.