BMW introduced the redesigned M4 a little over a year ago and it’s set to spawn a handful of special editions including a highly anticipated CSL variant. Caught undergoing testing on and around the Nürburgring, the hardcore model aims to be the ultimate driving machine as it’s expected to be lighter and more powerful than the standard model. It will also be a tad more aggressive as the high-performance variant is distinguished by a unique grille, which trades horizontal bars for a bone-like structure. The model also features a sportier front splitter and updated lighting units.

Moving further back, the car rides on lightweight wheels that are backed up by a high-performance braking system with bronze calipers. We can also see carbon fiber mirror caps and a larger rear spoiler. The model also appears to feature a lightly revised diffuser and a carbon fiber roof that is covered by camouflage. While the photos provide a glimpse inside the cabin, there isn’t much to see other that what appears to be an Alcantara-wrapped steering wheel. However, previous reports have suggested we can expect sport seats and plenty of carbon fiber trim.

 

The biggest mystery remains performance specifications, but the standard model has a twin-turbo 3.0-liter six-cylinder engine that produces 473 hp and 550 Nm of torque. The Competition variant ups the output to 503 hp and 650 Nm)of torque, and it’s natural to assume the M4 CSL will be even more powerful. How much more remains unknown, but rumors have suggested we could be looking at around 540 hp.

Rumors have also indicated the model will be offered exclusively with rear-wheel drive and an eight-speed automatic transmission. The latter decision will probably annoy purists, but it shouldn’t be too surprising as the Competition variant is automatic-only. Besides the upgraded engine, we can expect a sportier suspension and some weight savings. Unfortunately, we likely won’t learn specifics until the model debuts next year.