This standard applies to M2 and M3 class I, II and III city buses powered by LPG, gasoline/LPG, diesel/LPG. This standard specifies the technical requirements, test methods, inspection rules, marking, transportation and storage of passenger cars using LPG natural gas systems.
QC/T 689-2002 history
2002QC/T 689-2002 Technical conditions for liquefied petroleum gas passenger cars