Oil Filter change interval is widely defined as a mileage, expressed in Kilometres/Miles of the Vehicle driven. On the other hand, for convenience, repeatability and differentiation reasons, the Filter life time is evaluated in the laboratory test bench according to standard test methods. The Life Time is expressed in grams of calibrated dust injected into the filter inlet so as to clog it. The most commonly used test standard is ISO 4548-12 . So far, there is no widely known and recognized relation between the service time in kilometres and the dust holding capacity according to ISO standard. The purpose of the following study was to establish a relationship between ISO standard dust capacity and the ability of the filter to successfully achieve the service interval in 90% of cases. A large number of used filters were collected and analysed in order to conduct a statistical analysis. Impacts of fuel type, engine displacement and road conditions were identified. At the end a clogging rule was established. The paper concludes that for some filter applications, it is possible to reduce the required ISO dust capacity which opens the door to filter size reduction or enhanced engine protection through higher filtration efficiency.