The M2 could be the first model to use the new moniker.
Positioned between the standard M4 and the hardcore M4 GTS is the relatively new M4 CS. With a 460-horsepower (343-kilowatt) engine and a top speed of 174 miles per hour (280 kilometers per hour), it’s the most fun Coupe Sport model available in the BMW lineup... for now.
According to BMW M boss Frank Van Meel in an interview with Road & Track, BMW is set to revive its iconic CSL, or Coupe Sport Light, badge. The CSL designation will replace the current top-tier GTS moniker, and "[will be] the top-of-the-line track tool, made on the track for the track, just with a number plate," said Van Meel in the interview.
Along with added sporty elements to the exterior, the CSL model will also gain features like sticky cup tires, a coilover suspension, a roll cage, and yes, even a fire extinguisher. It will be the most hardcore variant in the M lineup, while the lower trim CS model will have more of an emphasis on comfort. Van Meel said that the CS trim will still be "a track tool, but with four seats."
For now, the company is staying quiet on exactly which models will gain the CSL designation first. Rumors suggest the M2 could get a CS version as early as January, and will be limited to just 1,000 examples worldwide. A more hardcore CSL model could come later in life with as much as 408 hp (304 kW), a significant bump over the current M2’s 365 standard horsepower (272 kW).
Only two BMW models have ever worn the CSL badge in the past. From 1971 to 1975, the 3.0 CSL wore the badge, and in 2003 the E46 M3 CSL (pictured here) was given the designation.
Source: Road & Track