The EPA has challenged some car companies on their gas tax claims . EPA generally taxes only a fraction of vehicles , while car companies basically use other methods . The Obama administration has pushed through tougher standards for better gas mileage . Korea 's Hyundai and Kia lowered fuel economy estimates for some 2012 and 2013 models after the EPA found discrepancies between agency results and data submitted by the company . Drivers have responded , often by saving money at the pump .
The EPA has challenged some car companies on their gas tax claims . EPA generally taxes only a fraction of vehicles , while car companies basically use other methods . The Obama administration has pushed through tougher standards for better gas mileage . Drivers have responded , often by saving money at the pump .