Abstract The UN / ECE 115 Regulation concerns technical requirements and methods of measurements for retrofit LPG systems to be installed in the motor vehicles already in operation In Poland, the 115 Regulation was adopted in 2004 but has not been observed. Regulation 115 is used in other countries, which created the need for tests. ITS has been conducted tests according to R115 since 2006. The technical requirements imposed by 115 Regulation include emission test, OBD testing, testing of maximum power at the wheels and testing the methods of the system elements installation in the vehicle. The article presents the requirements of the Regulation and the conclusions of the tests conducted at ITS on over 100 vehicles equipped with LPG systems. The paper presents: vehicle equipped with LPG systems tested at ITS as part of the statutory ITS work, time of switching over from running on petrol to LPG fuel during the driving test following a cold engine start, onset of the emission during the EUDC test following a cold start in respect to the value of the total emission in the emission test in accordance wit
