While we have no info concerning how this the X5 M was tuned, we’ve seen similar models defeat the previous-generation M3 quite a few times.
All things being equal, these two cars match up against each other pretty well. In fact, a few months ago we saw another rolling start race between them, where the X5 M jumped into the lead immediately and hung on until the finish line.
When stock, the X5 M is putting down 575 PS and 750 Nm (553 lb-ft) of torque compared to the E90 M3’s 420 PS and 400 Nm (295 lb-ft).
The difference is quite significant and if the M3 wasn’t much lighter, this race would have been a cakewalk for the SUV even if it wasn’t tampered with.
As it stands, the tuned SUV does the quarter mile in the mid to low 11s. This makes it a tough nut to crack, especially for an older model such as the E90 M3. On top of that, snow was beginning to come down on the track during the race, which at least meant that the low temperature favored the all-wheel drive X5.