BMW M3 CS due early 2023 with 405kW engine – report

An even higher-performance BMW M3 is reportedly in the works with more grunt from its twin-turbo inline six.

What appears to be an internal document detailing the BMW M3 CS has been published on Bimmerpost, outlining both left- and right-hand drive variants.

Production of both will reportedly start in March 2023, suggesting a reveal is imminent. Our photographers have already captured what appear to be M3 CS prototypes in testing.

The leaked document says the vehicle has all-wheel drive and produces 405kW of power from its S58T twin-turbocharged 3.0-litre inline-six, though doesn’t specify which transmission it uses.

BMW doesn’t currently offer a manual transmission with any of its all-wheel drive M3 and M4 models, suggesting an eight-speed automatic transmission is the likely choice.

That 405kW output is lineball with the rear-wheel drive M4 CSL, which also produces 650Nm of torque, though the M3 CS may be heavier as, even if it does include some of the weight-saving measures of the M4 CSL, there’ll likely be a marginal weight penalty with the M xDrive all-wheel drive system.

The M4 CSL has a tare mass of 1588kg, compared to 1743kg and 1738kg for the all-wheel drive M3 Competition and M4 Competition, respectively. A rear-wheel drive M3 Competition, for context, weighs 1693kg.

BMW stripped 100kg from the M4 Competition coupe to make the CSL, utilising more carbon-fibre but less soundproofing.

The M4 CSL also lost its rear seats, though the M3 CS could follow its bigger M5 CS sibling in featuring two rear buckets.

To make the M4 CSL, the M team also reduced weight by employing light alloy wheels, manually adjustable carbon bucket seats, lightweight M Carbon ceramic brakes, and carbon fibre-reinforced plastic for the roof, bonnet, boot lid and centre console.

Even with the extra 30kW over the M3 Competition, the CS won’t be able to match the outputs of the new Mercedes-AMG C63 S E Performance with its 2.0-litre turbocharged plug-in hybrid four-cylinder powertrain.

The AMG has total system outputs of 500kW and 1020Nm of torque, though it has a kerb weight of 2165kg – considerably porkier than any M3 or M4 due partly to the weight of the battery.

Mercedes-AMG claims a 0-100km/h time of 3.4 seconds, though despite being down on power and torque the M3 Competition xDrive has an almost identical 3.5-second sprint time.

The BMW M3 line has already been confirmed to be expanding in 2023 with the launch of the Touring, the first such time BMW has offered an M3 wagon.

It’s coming here early next year, offered only in a simple all-wheel drive 375kW/650Nm Competition variant and priced from $177,500 before on-road costs.

MORE: Everything BMW M3