bmw’s new 2023 m4 csl is a focused track-day special edition that is optimized for those who are willing to give up a chunk of daily-driver livability for substantially enhanced performance. csl stands for competition sports lightweight, and the specs show this to be more than a mere marketing term. they also show that this car will almost certainly be a brute that won’t appeal to everyone.
it’s powered by the same twin-turbo 3.0-liter inline-six that powers the m4 competition, but the csl’s peak turbo boost has been raised from 24.7 psi to 30.5 psi, a 24 percent increase. the dual-circuit cooling system has been upgraded to suit not merely the extra power, but also the rigors of track use. the result is 543 horsepower, some 40 hp more than the competition, with the same power peak of 6250 rpm. maximum torque is also unchanged at 479 pound-feet, which means the eight-speed automatic transmission and driveline from the competition can be used as before, right down to the automatic’s internal ratios and the final-drive ratio inside the m sport differential. the shift points have been performance-optimized, however, and the engine and transmission mounts have been substantially stiffened. there should be far less slack and windup in the power delivery, but an increase in cabin vibration is almost certain to be a side effect.
the effects of this extra power are magnified by a massive 240 pound weight reduction. each of the m4 competition’s horsepower has 7.7 pounds to move around, but the extra power and lighter weight of the csl drops that significantly to 6.7 pounds per pony. bmw claims that it will get to 60 mph in 3.6 seconds, compared with the competition’s claimed 3.8 seconds, but we think it’ll do better.
the csl is a two-seater that sheds its rear seat and seatbelts to save 46 pounds right off the top. beyond that, its one-piece carbon front buckets save 53 pounds, but you can choose to add 32 pounds back if you order adjustable carbon seats. another 33 pounds in savings comes from the use of lightweight sound insulation—and quite possibly less of it—in certain areas. more carbon-fiber reinforced plastic (cfrp) is used inside and out, including for the center console that saves 9 pounds. at the tail end of the exhaust, another 9 pound savings comes from the use of a titanium silencer that’s tuned so it “can be fully appreciated inside the cabin where it provides the driver with accurate acoustic feedback in response to movements of the accelerator and clearly conveys the engine's performance characteristics.” which is a roundabout way of saying it’s louder.
the csl comes standard with the 275/35zr-19 front and 285/30zr-20 rear high-performance tire combination that’s optional on the competition, but the wheels are mounted on csl-exclusive forged alloys with slender spokes that shave off more weight. carbon-ceramic brakes that are optional on other m4s are standard here, and the wheels, brakes, and certain lightweight suspension components add up to another 46 pounds saved, with much of this being unsprung weight.
the suspension squats some 0.3 inch lower than the competition, and it has been recalibrated with csl-optimized springs, adaptive damper valving and software, and altered stabilizer-bar tuning. also notable is the use of additional monoball joints in certain rear suspension links instead of rubber bushings in the interest of more precision when on the track. this last tidbit reminds us of similar suspension changes made to the porsche cayman gt4 rs, which delivered stellar handling as a result, as well as questionable livability.
all signs point to a much more capable and raw bmw m4 that will indeed be a more potent track-day weapon. there’s a single-minded approach at work here, and it should absolutely appeal to those who want to put their m4 on the track. how many bmw fans are looking for what the m4 csl has to offer? we’ll see once we know how long it takes the 1000 units—each priced at $140,895—to sell out.