California drivers already pay more for gasoline than motorists in just about every other state.

But even after taking into account state gas taxes, blending requirements aimed at reducing air pollution and other environmental and climate fees attached to each gallon of fuel, it appears drivers in the Golden State pay a lot more than they should.

UC Berkeley professor Severin Borenstein calls the price differential “California’s mystery gasoline surcharge” that roughly translates into a premium of 20 to 30 cents on every gallon pumped in the state.

Read more at The San Diego Union Tribune