This paper considers the equity implications of vehicle emissions taxes by examining the incidence of a tax on local pollutants. It uses emissions data from the California Air Resources Board and household vehicle and income data from the US Consumer Expenditure Survey. It incorporates household price responsiveness that differs across income groups into a consumer surplus measure of tax burden. Since poor vehicle owners spend more on miles as a proportion of their income and drive vehicles that pollute more per mile than those owned by the wealthy, the incidence of tax on vehicle emissions falls relatively heavily on them. This burden, however, is mitigated to some extent by low vehicle ownership rates and high price responsiveness in the lower half of the income distribution. A uniform tax on miles that does not distinguish between dirty and clean vehicles is less regressive than the emissions tax.