As easy as it is to look at Oregon and not believe how stupid the leadership is, or how far down the Blue rabbit hole the state has gone, we do not yet have a sales tax, so only a $.40 gallon state tax.
Most states have a fixed per gallon tax, plus the regular sales tax. Make it a per gallon tax only. States get a windfall when prices go up, which compounds the cost to the buyer.
It's so subsidized, you pay half of what it's worth at the pump. Not sure, but I heard once it actually costs less to buy than it does to produce. In America, anyways.