The analysis in this article examines the impact of reducing the excise tax on gasoline and diesel fuel on the U.S. economy. The analytical approach used consists of a computable general equilibrium model composed of 14 producing sectors, 14 consuming sectors, 6 household categories classified by income, and a government. The effects are examined of a 4.3 cents per gallon reduction in the excise tax on gasoline and diesel fuel on prices and quantities. The results suggest, for example, a decrease in the tax would result in higher output by the producing sectors (by about $2.86 billion), an expansion in the consumption of goods and services (by about $3.48 billion), and an increase in welfare (by about $3.59 billion). The government would realize a decrease in revenue of about $2.37 billion. When subjected to a sensitivity analysis, the results are reasonably robust with regard to the assumption of the values of the substitution elasticities.