2023 BMW M4 CSL First Drive Review: Light It Up
BMW says M is the most powerful letter in the world, but the addition of the letters CSL makes it both more powerful and lighter too. That basically sums up the M4 CSL, which cranks performance and removes weight to increase driver engagement. Simple concept, but this lightweight suffix comes heavily laden with responsibility.
Originally meaning Coupe Sport Leichtbau (or Lightweight), and officially Competition Sport Lightweight in today's genre-fluid times, CSL first appeared on the 3.0 CSL 'Batmobile' launched soon after BMW M was founded 50 years ago.
The CSL won the 1973 European Touring Car Championship and laid the groundwork for the M road cars we know today, but BMW has dusted off the CSL suffix only once since, and that was for the 2003 E46 M3 CSL now revered as one of the best M cars of all time, if never sold in the US.
So the pressure to deliver on only its third outing in half a century is immense. Good news, though, because while production is capped at 1,000 units, this new two-seat CSL is coming stateside… and we're happy to report it does indeed live up to the storied badge.
Exterior Design: Visually Challenged
Let's not get too ahead of ourselves with the good news stuff, because it's still a stretch to call the M4 either attractive or classy, especially when viewed alongside its predecessors. It does, however, exude purpose. Perhaps most striking are LED Laserlight headlights with yellow accents that echo the GT racing cars, plus there are new rear lights, aero flicks on the front splitter, a new ducktail rear spoiler, and a carbon fiber rear diffuser, all of it topped off by a new design of alloys and a slightly lower stance.
BMW M 50 Years badges are standard, replacing the standard blue-and-white emblems, red accents are a little (other) Batmobile, and there's a choice of Frozen Brooklyn Grey metallic (optional), with Alpine White or Black Sapphire standard. Black still works better IMHO, helping tone down that toothy front grille.
Weight Saving: Unleash The Leichtbau
BMW's playbook states that a CSL must weigh substantially less than the car it's based on. By how much nobody is exactly sure, but it's interesting that BMW used the slightly anonymous GTS moniker for the previous two hardcore M3/M4 models, which were 165 lbs and 10 lbs lighter, respectively.
The M4 CSL officially drops 240 lbs at a US curb weight of 3,640 lbs, which is more than the GTS models and just 3 lbs less than what was cut from the E46 M3 CSL (though the M4 CSL saving represents a smaller slice of a larger pie since it's a much heavier car overall).
Nonetheless, 240 lbs remains a significant and impressive amount to extract from a modern car, especially with climate control and the full BMW Live Cockpit infotainment system onboard (a sensible decision, especially given 85% of E46 M3 CSL owners added comparable equipment back in).
To break that figure down, a carbon fiber hood and trunk join the carbon fiber roof that's already standard on the M4, and together with a few other bits of carbon, save 24 lbs. The titanium exhaust silencer saves nine lbs. Carbon-ceramic brakes are an option on the standard M4 but standard here, plus the CSL gets bespoke lightweight springs and struts and new lightweight alloys, saving 46 lbs.
Inside, new carbon seats are 53 lbs lighter (our test car featured electrically adjusted carbon-shelled seats normally optional on other M4s, saving 21 lbs), and the rear seats are removed, saving a further 46 lbs. BMW says 'lightweight sound insulation' accounts for 33 lbs.
There's some chipping away at the kidney grilles (you can see the radiator is much more exposed), the climate control and floor mats, and even the rear lights are, well, lighter, giving the final eight-pound push over the finish line.
Performance And Handling: Faster, Sharper
Performance and chassis revisions complement the reduced weight. The M4's S58 3.0-liter twin-turbo six is boosted by 40 horsepower to 543 hp at the same 6,250 rpm peak, with torque unchanged from the M4 Competition at 479 lb-ft from 2,750 rpm.
An eight-speed auto is standard - interesting given the manual is lighter, but perhaps quick shifts at the Nurburgring are the priority - but the CSL is rear-wheel-drive only. Add it up, and you get 0-60 mph in 3.6 seconds and 191 mph flat out.
The chassis is 8 mm lower with new helper springs front and rear, adaptive dampers are standard, plus there are uprated anti-roll bars, stiffer engine mounts, a bespoke cast aluminum strut brace, and a solidly mounted rear axle for extra precision. While tire sizes are unchanged (a monster 275-section for the 19-inch front tires and 285 20s for the rear), you can spec your CSL on super-aggressive Michelin Cup 2 Rs - factory driver Jorg Weidinger pulled a 7min 20.2sec Nurburgring lap on the same rubber, but the car we sampled was shod on Pilot Sport 4S tires that are less effective in the dry but way better in the wet.
There's no talk of downforce in the press material, despite the aero flicks at the front and the ducktail/diffuser at the rear, but clearly, they add some positive squish into the surface.
At The Wheel: Hardcore Done Right
For a car intent on tearing tenths of seconds to shreds, the M4 CSL is impressively easy around town - the suspension feels tight yet supple in its softest setting, the steering twirls easily and you sit comfortably in leather seats with climate control, sat-nav and stereo all at your fingertips. Despite extra road noise, I'd happily daily an M4 CSL, suffice to say it'd be wasted on a typical commute.
The titanium exhaust gives the CSL an angrier if tinnier bark from outside, though thankfully it sounds fuller-bodied when you're plugged into the low-set carbon bucket seat. The 3.0-liter turbocharged motor remains a wonder of extraordinary bandwidth, performance, and throttle-controllability, with, if anything, heightened response. It does have a charmless, bassy drone in the mid-range, but reaching for the high notes is a fury of speed and intense, fast-paced noise that proves far more entertaining.
Additional performance/weight saving is apparent, but despite unchanged torque, the CSL feels substantially more muscular in the mid-range than even the standard model, itself pretty stout. That's no doubt because of the reduced weight, but on more challenging roads, it does have the unfortunate effect of giving the CSL a big-chested turbodiesel vibe - a sensation that performance is running away with itself, and that short-shifting through gear ratios rather than extending the engine to its impressive 7,200-rpm redline is what's required here. Straighter roads showcase the stretch of this engine, but the emphasis on short-shifting through turns does dock a point from driver engagement.
There are no claims for more intense or faster gearshifts, but they seem to hit harder - perhaps there has been some recalibration to really prove an auto can deputize for a dual-clutch, or perhaps it's the stiffer engine mounts and solidly mounted rear axle. Either way, I found myself winding back from the third and most aggressive shift setting, which thumps pretty abruptly.
Find space, and the CSL is so light on its feet and keen to change direction that you'd guess way less than the official 3,640 lbs, with the reduction in unsprung mass particularly palpable. The steering is pinpoint accurate, responds instantly to every instruction, and even musters some feel, but incisive as it is, there's also a calmness to how the M4 carves corners, no doubt helped by its supple suspension. It's good on the 4S tyres, but the Cup 2 Rs must bite like ice skates.
Really tap the performance and the CSL feels dramatically rear-biased - kind of obvious given it is rear-wheel drive, but it's a very pronounced effect that's perhaps a little intimidating initially. But with such strong bite from the front tires and surprisingly good traction given the layout and power characteristics, you build confidence to really lay into this car. Push the limits with all the stability systems off and the CSL is less fluid than the standard M4, simply because its limits are higher and it lets go less willingly, but 10-stage traction control eases you into that.
All in, it's an unusual mix of delicacy with thumping performance that makes for an entertaining way to cover ground quickly.
Verdict: Living Up To The Legend
The CSL name might come loaded with pressure, but the M engineers have risen to the challenge. The fact that the standard G82 M4 is such a step over its predecessor helps, but to those foundations, the CSL adds a lighter, more immediate dynamic, deepening driver engagement. It feels much more alive and reactive. What's particularly impressive is despite a focus on hardcore thrills, the M4 CSL manages to retain such civility. Yes, we'd prefer less mid-range thump, but there's no question this CSL delivers on its promise.
All this comes at a price, of course - the M4 CSL bases at $139,900 plus $995 destination, some $61k up on a rear-wheel-drive M4 Comp Coupe. But with global production limited to 1,000 units and that CSL badge on the trunk, it's sure to be sought-after.