The exhaust aftertreatment systems of diesel passenger cars have been equipped with diesel particulate filters since 2009 when the EURO 5 standard was introduced. This device is a trap for particulates, which originate from internal combustion engines in soot form. These particles must be filtered because they are able to enter the bloodstream through the human respiratory system and can cause an adverse effect on health. Investigations conducted after the 2016 diesel scandal concluded that gasoline engines with direct injection systems commonly in use today, also produce a high number of particles, therefore they must be equipped with gasoline particulate filters. The current EURO 6d TEMP regulation introduced in September 2017 specifies that the NEDC-regulation has to be replaced gradually with the WLTP investigation and the RDE realistic vehicle tests, thus making the real results of the measurements impossible to avoid. Also the particulate emission per one hundred kilometers will be observable in case of direct injection gasoline engines. This paper presents the formation of soot particles during the combustion processes of diesel and gasoline engines, the deposition of particles in particulate filters and explores and analyses the differences between the regeneration processes due to the deposition of particles.