Consumer behavior in the choice of motor fuel for flexible or dual-fuel vehicles will be a key factor in creating and maintaining stable markets for new fuels. This paper presents an analysis of refueling behavior of natural gas vehicle owners based on a survey of natural gas vehicles in Canada. Models of owner satisfaction and frequency of CNG choice are estimated to evaluate the importance of performance, range, refueling convenience, and other factors in the fuel choice decision. The cost advantage of natural gas is of paramount importance for Canadian natural gas vehicle users. Refueling convenience is also essential for overall satisfaction as well as being a major factor in frequency of natural gas use. Alternative fuels will not only have to be cost-competitive with gasoline but, initially, will require a cost advantage to overcome range limitations and refueling inconvenience.