The current 2021 U.S. average tax rate stands at 36.83 per gallon for gasoline and 37.85 for diesel fuel. CoPilot used 2021 data from the American Petroleum Institute to rank states with the highest gasoline and diesel taxes. The states are ranked by the 2021 gasoline tax, ties are broken by the 2021 diesel tax, and further ties are left. Both the state excise tax and other state taxes and fees are included in the tax data points. While this data is current as of Jan. 1, 2021, other federal, state, and local fees could be applied depending on an individual’s vehicle and fuel type, and tax rates are always subject to change based on state legislation. CoPilot also included a data point from the U.S. Federal Highway Administration showing total gasoline use in every state during 2019, the most recent year available.