Back in March, a juicy rumor emerged about the prospects of a power bump for the M4 LCI due to come out in 2024. The report alleged BMW’s engineers would massage the inline-six engine in the xDrive version of the high-performance coupe. Fast forward to this week, three documents from an internal database have been published on the Bimmer Post forums and seem to confirm the twin-turbo 3.0-liter unit is indeed getting some extra ponies.

The “S58” engine is listed as having 390 kilowatts, which works out to 523 horsepower. It’s an extra 20 hp compared to the M4 Competition on sale today. The three docs refer to left- and right-hand drive cars destined to be sold in Europe and another LHD vehicle for the United States, all sharing the same 390-kW output.

By now, you’re probably wondering whether the rear-wheel-drive M4 Competition will benefit from the power increase. According to the forum member who posted the documents, that’s apparently not going to be the case. Consequently, the M4 Competition RWD will soldier on with 503 hp. Similarly, the base M4’s output is expected to remain unchanged, at 473 hp. Of course, we all know BMW deliberately underrates its engines as dyno tests have revealed a lot more power than what the specs sheets say.

According to the same documents, production is scheduled to commence in March 2024 for both Europe and the US. That would imply a world premiere in the first three months of next year. In the US, the M4 has already entered the 2024 model year, so the LCI is likely to be sold as a 2025MY.

The initial report from earlier this year claimed the M3 Competition xDrive (G80) would echo the two-door version by gaining extra power as well. Spy shots have revealed BMW is planning an early LCI for the M3 Touring (G81) as well, and since the super wagon is sold strictly as a Competition model with AWD, perhaps the AMG C63 Estate rival is also bound to put on some extra muscle.

Much like the long-roof M3, the M4 Convertible is also a Competition affair with xDrive, so perhaps BMW M intends to tweak its six-cylinder engine as well to align all models to the rumored output.

523 hp would still be down by 20 hp compared to the M3 CS and M4 CSL, with the M4 CS coming next year likely to have 543 hp as well. For the ultra-exclusive 3.0 CSL, BMW extracted an additional 10 hp for a grand total of 553 hp but torque took a big hit since it was limited to 550 Nm (404 lb-ft) instead of the full 650 Nm (479 lb-ft) after fitting a six-speed manual gearbox.

Source: Bimmer Post