60 - 70, but its the potholes and uneven joints of highway to overpass. I always seemed to find the worst ones on my commutes through and around Baltimore city (BW Parkway in particular). I have 19" on remaining 2 BMW = no problemsBy the way, I've had an x6 with run flats since 2014, 70k miles and two tire replacements -never had a breakage, how fast or where do you drive???