This paper analyzes the dynamics of U.S. automobile gasoline consumption since 1975. Using background literature on the history of domestic fuel economy and energy policy, I establish a conceptual model that explains historical trends in adoption of increased fuel economy. I then create a system dynamics simulation model to understand the relationship between increased fuel economy standards and potential changes to gas tax policies. The model suggests that when increases in mandated fuel economy are not conducted in an environment with rising fuel costs, fuel economy improvements may be directly counteracted by shifting tastes of consumers towards larger automobiles with lower fuel economy.