Someone correct me if I am wrong, but I believe most of the taxes on gas are per gallon not the dollar amount.
Depends on the tax. Road tax, yes per gallon. Corporate taxes and some states sales taxes are based on the dollar amount.
the federal excise tax and state highway taxes are charged per gallon. here in illinois, additional state, county, and city SALES taxes are charged per dollar, including the per gallon taxes charges. so we get to pay tax on tax.
You are not wrong. Most are. Every state charges an excise tax per gallon, that rate is a fixed rate, regardless of prices. However, 30 some-odd states also attach other fees, some may be fixed, but many are variable, based on the cost of fuel (sales/use taxes). See my post 35, last link, for that breakdown.
There are two types of taxes that you see at the pump. Sales tax (if your state has it) and a per gallon tax.
In California, there is 18 cents per gallon plus a 6 percent sales tax. In addition, there is an 18.4 cent federal tax.
California residents pay roughly 36.4 cents per gallon, plus another 25.5 cents per gallon sales tax (at sale price of $4.25 per gallon) for a total per gallon tax of about 62 cents per gallon.
On a typical 16 gallon fill-up costing $68.00, $9.92 is tax paid at the pump.
http://www.californiagasprices.com/Tax_Info.aspx