As of 2015, Alaska has the lowest gas tax, with a state fuel tax of 11.3 cents per gallon, while Pennsylvania has the highest gas tax, with 50.5 cents per gallon, states USA Today. Alaska has a 3.9 percent tax as a percentage of price, while Pennsylvania's is 21.3 percent.
Some other states with low gas taxes include Arizona, Oklahoma, New Jersey and South Carolina, states USA Today. Other states with some of the highest taxes on gas include New York, California, Connecticut and North Carolina. The reason why the tax rate is so high in Pennsylvania is because the tax is based on fuel transactions at a wholesale price. While tax rates on gas in Alaska are low, the overall gas price is one of the highest in the United States.