Has the gas tax rate increased? Yes. Beginning July 1, 2017, the gas tax rate is increased to 24 cents. See important notice 17-08 for rate increases for subsequent years. May 10, 2017 19:20 Related articles What are the new refund tax rates for gasoline and diesel? Has the undyed diesel tax rate increased? TNTAP: Filing a Sales Tax Return Who is entitled to the tare allowance for motor fuel taxes? Has the undyed diesel tax rate increased?