none of the fuels is clean fuel. comment Share with your friends Share 2 Dharmesh answered this BECAUSE ALL FUELS RELEASE POLLUTION ON COMBUSTION. BUT CNG AND LPG ARE CLEANER FUEL 10 View Full Answer Devansh Kaushal answered this All fuels emit pollutant gases on combustion 3 Sushant Saurav answered this CNG and LPG are clear fual . Exept these all produces harmfull pollutants on combustion . 7