The iglidur Expert system works on the basis of hundreds of thousands of measurements performed systematically in our tribo laboratory . Usually, in these tribological tests, wear-related material losses are determined by measuring the volume of wear and the weight loss of the bearing. In our experience, it is more practical to directly measure the loss of wall thickness. For this reason, we always measure the wear behaviour of a plain bearing in μm/km, which is the loss of wall thickness for every kilometre of running performance. In this way we can optimally judge how much clearance arises in the customer application after a certain time – that is, when the wall thickness loss has enlarged the bearing clearance to the maximum tolerable value.