Is BMW deliberately underrating the engine’s power? It wouldn’t be the first time.
It would seem BMW has been caught lying, but in the best possible way. In typical German automaker fashion, there are signs the Bavarians have intentionally underrated the twin-turbo, inline-six engine powering the new M3 and M4. Illinois-based aftermarket specialist IND Distribution got a hold of a completely stock coupe and conducted an independent dyno test.
BMW may say its S58 engine produces 473 horsepower (353 kilowatts) at the crank for the non-Competition models, but in reality, the six-cylinder mill generates nearly as much power at the wheels. IND Distribution says the rear-wheel-drive M4 they tested produced 464.92 hp (346.7 kW) at the wheels. As for torque, the engine is officially rated at 406 pound-feet (550 Newton-meters) at the crank, but it pushed out 408.55 lb-ft (553.9 Nm) at the wheels during the dyno run. For the full story, check out this article from Motor 1.