Published by ciadmin on February 21, 2025 As of January 1, 2025, state taxes and fees on gasoline and diesel fuel averaged $0.33 per gallon (gal) of gasoline and $0.35/gal of diesel fuel, according to our table on federal and state motor fuel taxes. Since July 2024, average taxes on both gasoline and diesel have remained nearly flat, increasing less than half of one cent each.