BMW’s controversial performance coupe is set to get even hotter, with rumours suggesting the upcoming CSL will pack 403kW and rear-wheel drive.

The 2023 BMW M4 CSL could offer over 400kW when it arrives in mid-2022, according to new reports.

BimmerPost forum member and reputable BMW insider ‘ynguldyn’ reports the track-focused variant of the new-generation ‘G82’ M4 coupe will enter production in July 2022 – reviving the German brand’s iconic ‘Coupe Sport Lightweight’ moniker last applied to the E46 M3 CSL of the mid-2000s.

Power is set to come from an uprated version of the standard car’s 3.0-litre twin-turbocharged inline-six engine, developing around 403kW – a healthy bump over the current M4 Competition’s 375kW (and 650Nm) output.

In line with its name, the CSL will send power exclusively to the rear wheels, eschewing the new M4 Competition xDrive’s all-wheel-drive system to save weight.

MORE: 2022 BMW M4 CSL spied – UPDATE: See and hear the CSL in a new video

It’s not clear what transmission will be bolted to the engine, though the Competition’s eight-speed automatic is most likely, given the CSL’s track-focused intentions, and that BMW’s six-speed manual can’t handle the torque the uprated engine would provide.

Speaking to Australian media in September 2020, BMW M CEO Markus Flasch confirmed the manual’s limitations: “You see that the torque output of the manual transmission [M3 and M4] models is limited to 550Nm, this is because the transmission can’t put more torque through it.

“On the other hand, the weight benefit of the manual transmission is 25 kilograms, so I think it’s a very, very interesting element of the M3…”

Those performance figures would put the new M4 CSL on par with the track-focused Alfa Romeo Giulia GTA, which packs 397kW and the same eight-speed transmission, but four doors.

Like the Alfa, the forum post claims the limited-run M4 will use “lots of carbon bits” and an Alcantara steering wheel to differentiate it from the Competition on which it’s based, along with a new set of alloy wheels.

Spy photographers caught what is believed to be our first look at the new M4 CSL earlier this year (pictured throughout), with the prototype snapped featuring a larger front splitter, ‘ducktail’ boot lid spoiler, and a lower ride height.

Production of the 2023 BMW M4 CSL will commence in July 2022, according to ynguldyn – two years ahead of the new M4’s mid-life facelift, slated for March 2024.

The user claims the model will be built as part of a “very short production run” – and while no mention is made of production quantities, expect only a few hundred units to be built.

Such a timeline roughly aligns with the previous-generation, track-focused M4 GTS, which debuted in late 2015, passing through a short production run ahead of a mid-life facelift for the entire M4 range in early 2017.

BMW M has previously shown interest in reviving the CSL badge, with CEO Markus Flasch telling CarAdvice in 2019: “CSL stands for light weight, CSL stands for racetrack ability, and for the purest M character that you can achieve on a car that’s still got licence plates on it.

“We will see more limited editions, especially models like the CS and you can imagine the CSL. We won’t do this on every car but I would go as far as to say that we also don’t have to stick to coupes only,” he said, adding that “we won’t see the GTS sub-brand in future… There won’t be a GTS in parallel with CSL.”