The purpose of this research was to study opinions of private car users after the installation of liquefied petroleum gas (LPG). The samples used in this study included male and female car users who had installed LPG and has refilled the gas at one of 3 gas stations in Chachoengsao Province. The sample group was purposely random of private car users who incidentally went to refill gas at the gas stations. The questionnaires were distributed to 500 private car users. The integrity of the collected data was verified before processing by using Statistical Package Software
	The results of the study indicated that:
 	1. Additional costs problem of private car users who installed LPG in Chachoengsao Province, as a whole, were at minimum level.
	2. Engine problems of private car users who installed LPG in Chachoengsao Province, as a whole, were at minimum level.
	3. Health and environment problems of private car users who installed LPG in Chachoengsao Province, as a whole, were at minimum level.
