While tyre abrasion is about to be regulated as well as particle emissions emission of friction brakes, the tyre and road wear particles gain more attention in research. In the past, emission behaviour of heavy duty vehicles was estimated on extrapolation out of abrasion measurements. In order to close this knowledge gap, this study aims to make a first comparison of the TRWP emission behaviour of light duty vehicles and heavy duty vehicles under real driving conditions. The results of this study cannot confirm the big difference in emission factors between LDV´s and HDV´s. However this study also highlights the limits of the conducted measurements, suggesting, that under current conditions, emission factors should not be estimated because of sampling and measurement method limitations, which need further refinement.