BMW is readying a lightweight M3 CS as the four-door sibling of the M4 CSL, and our spy photographers were able to capture it testing out on track. The car’s chief rival will most likely be the recently unveiled Mercedes-AMG C63 S, so this hot M3 will need to be quite the special vehicle to take it on.
Styling-wise, the upcoming M3 CS will get all the aesthetic upgrades the M4 CSL got, which include a new front fascia, a more aggressive aero kit, and new wheel designs. There’s also the possibility of an integrated rear ducktail spoiler and new OLED taillights, but this particular test car doesn’t seem to be sporting either of those.
Read More: 2024 BMW M3 CS Spied As A Four-Door M4 CSL
As for what’s expected to power it, the most likely candidate is an uprated version of the regular M3‘s 3.0L twin-turbo inline-six. In the M4 CSL, this engine sends 543 hp (550 PS / 411 kW) and 479 lb-ft (649 Nm) of torque to the rear wheels, and it will likely do the same in the M3 CS. Other things likely to be carried over from the M4 CSL are upgraded chassis tuning, beefier brakes, lighter suspension components, and stickier tires.
One thing the M3 CS likely won’t get from the M4 CSL is its rear seat delete since this is the sedan. That being said, it’s possible that we could see two individual seats in the rear like what was done with the M5 CS. There will almost certainly be other drastic weight-saving measures, namely in the form of carbon fiber replacements for the roof, hood, trunk lid, and bucket seats.
The last M3 CS was 110 lbs (50 kg) lighter than the normal M3, and the new M4 CSL shaves 240 lbs (109 kg) off the regular M4’s curb weight, so we’d say it’s safe to expect around 150-175 lbs (68-79 kg) in weight savings for this new M3 CS. Should that be the case, given its expected power figures, the car would have a power-to-weight ratio of 0.148 hp/lb, which is comparable to the heavier C63 S’s 0.149 despite the Mercedes having over 100 more horsepower.