Estimating long-term vehicle ownership and energy use is essential for national transportation planning, especially for addressing policies regarding climate change. In this paper, long-term vehicle ownership and energy use in Korea is estimated according to income and fuel price scenarios. A modified form of a quasi-logistic growth function is employed to consider the causalities between vehicle ownership and independent variables. Vehicle ownership has been identified to be more sensitive to income change than to fuel price expectations. The likely fuel price increase evaluated in this research would not deter people from buying cars. This implies that future transportation energy conservation policies should be based more on transportation demand management (TDM)–type policies.