There were 3 tyre options available and I stayed with the Pirelli brand, opting for the Rosso non run flat version. They are BMW star rated, and have the same load index and speed rating as originals.
The X3 felt instantly more planted, with less tyre roar on poor surfaces. It no longer skips over road joints and is a much nicer place to be. Adjusting the tyre pressures can give quite varied ride characteristics, but I have settled on 33 psi front and 34 psi rears (cold tyres). Being an M Sport, it used to twitch about on undulating surfaces, and again this has been eliminated, the result is I can drive faster over them, without making passengers feel they are on a river cruiser.
To compensate for the lack of run flats, I have permanently stored an air compressor, slime, tyre plug kit, a few tools and emergency torch in the underfloor storage area. On longer journeys I also take the emergency jack with me. BMW don't list one for the X3, but the one listed for the F15 X5 fits. Bought it directly from BMW circa £70. It definitely works as i swapped winter's to summer's at home.
Hope that helps
