74k on mine. Expansion tank died at 73k and change.

JCL is correct -- it isn't miles, it is how those miles are accumulated (and the climate has to be considered too).

On the ones that have failed, anyone using anything but BMW coolant (plus water, of course)?

__________________
Kirk
Las Vegas
2016 X5 40e Mineral White/Black Dakota Leather, ZLL, ZCW, ZDA, ZDB, ZPP, multi contour seats, rear side window shades, HK stereo
2011 E90M3, 6-speed manual