BMW exhaust systems have been a mixed bag in the past couple of years, with the M3 coming short at first. But it seems the company has learned its lesson since this prototype is beyond reproach. For a twin-turbocharged inline-6, you couldn't ask for more.
And despite new emissions regulations forcing the X3 M to have a gasoline particulate filter, the model still has a deep tone. This is coming from the S58, an evolution of the S55 from the M3/M4 and the B58 fitted to the regular X3. It's believed that the stock configuration will have somewhere between 460 and 480 HP, with the Competition Package immediately boosting that number to 500 HP.
The two performance SUVs need that kind of power due to because the competition is already fierce. We have the Mercedes-AMG GLC 63 S matching the Alfa Romeo Stelvio Quadrifoglio at 510 ponies. And there's also an indirect rival from Jaguar, the monstrous F-Pace SVR.
It's not just about power, as agility and control also need to play a part here. That's why the M models have an all-new suspension, M compound brakes with ventilated disks, M xDrive, and a mechanical rear differential.
The design is a matter of personal taste, but we think the X3 M has more presence than the Alfa yet it can't match the premium look of the AMG. We'll know more when the model comes out, which is probably very soon.