BMW intentionally underrates the engine’s horsepower? This wouldn’t be the first instance.
BMW may have been lying but it was done in the best way. Bavarians intentionally underestimated the twin-turbo inline-six engine that powers the new and M4. This is typical German automaker behavior. IND Distribution, an Illinois aftermarket specialist, obtained a fully stock coupe and performed an independent dyno-test.
IND Distribution calculates that the engine produces approximately 547 hp (408 kW), and 480 lb-651 Nm at the crank. BMW claims the M4 Competition, which is hotter, has 503 horsepower (375 kW) as well as 479 lbft (650 Nm).
Although the “15 percent rule” is controversial as some argue that newer cars only lose around 10 percent from their crankshaft to their wheels, even so, the lower output numbers would still place the base model very close to the official BMW M4 Coupe Competition rating. It is also important to note that the car tested and certified by IND Distribution was still within the break-in period. The engine should produce more power as it accumulates miles.
The Dyno test results can vary for the same car so it is best to be cautious and wait until the subsequent evaluations of these new S58 models. This will give you a better idea of the output ratings. The new M4 seems to have more power than the advertised, judging by this Dynojet 424 test.
Already signs point to a hotter M4 being launched in 2022. It may be equipped with the CSS suffix which could bring an increase in power. BMW is finishing up the M4 Convertible in time for the summer launch. The first M3 Touring will be available next year. The next generation M2 Coupe could inherit the same engine but be tuned to avoid conflicting with its bigger brother M4.