BMW is getting its next-gen M3 performance sedan/saloon ready to rumble, and we cannot help wondering: how powerful is it, really? Based on this video with the X3 M being measured at a dyno, we would venture as far as to say: pretty damn powerful.
The latest X3 M comes equipped with the BMW S58 engine rated at either 480 hp / 358 kW (standard) or 510 hp / 380 kW (Competition). It is official that the M3 sedan gets the exact same engine model. However, when measured at the dyno, the SUV actually outputs as much as 498 PS (491 bhp, or 366 bkW) to the wheels. This is especially interesting, since the manufacturer-provided performance rating is usually only true at the crank, whereas transmission losses result in no more than 90% of power reaching the wheels. In other words, the effective brake horsepower of the X3 M should lie in the 450 area – but it is much higher.
This prompts two possible conclusions: either the German automaker has found a way to optimize the transmission even further, or the engine is more powerful by design than claimed. Experts tend to believe the latter version, estimating its real output at 550 hp (410 kW).