Increasing CO2 emissions from vehicles is becoming a major concern in automotive society, and variety of future types of cars are intensively investigated. However it is not clear which level of performance and cost must be achieved for the future cars to be available in a market and how much percentage of cars is necessary to be replaced by the future cars for the conservation of environment. The objective of this paper is to evaluate the possibility of market growth of future cars, as hybrid cars, electric vehicles and fuel cell cars, based on the performance and economic aspects. This paper investigates the emission reduction potential of these vehicles, and also compares the composition of vehicle types and emissions for a variety of scenarios of consumer characteristics, economic growth, fuel price, performance of cars, and carbon tax control measures. A model of user preference of cars was established from the statistic analysis of past data. The cost and performance of each type of car was estimated based on data from past trend in Japan and literature. The result of the analysis shows that electric cars and vehicles with hydrogen fuel cells have the best potential for reduction of carbon dioxides. During the next 20 years, hybrid vehicles with engine and electric motor will take a major market share, and cars with fuel cells will appear from around 2015. Substantial numbers of CNG cars and some percentage of electric vehicles will be accepted by the market, if the running range and infrastructure are not limiting conditions. Because of the improved efficiency of future vehicles, carbon dioxide emissions from passenger cars will be suppressed until 2015, then emissions will start to increase due to increased transportation demands, when GDP growth rate is assumed to be 2%.