The Sierra Club says six states have proposed legislation this year that would add to the cost of owning an electric vehicle, worrying clean energy advocates who say owning emissions-free vehicles should be incentivized rather than taxed. States with new EV-fee bills include Indiana, South Carolina, Kansas, Tennessee, New Hampshire, and Montana. About 10 other states already have similar fees instituted. Advocates of the new fees say they are necessary to make up for falling gasoline taxes, which are used to fund road upkeep, as vehicles have become more efficient, and EVs would avoid the cost altogether.