Tax on "Dirty Fuels"

Oil producers WILL drop the price of crude to sufficiently stifle American alternative fuel efforts (The Saudi Oil Minister said so in a 60-Minutes interview). Can we get Congress to impose a pricing "floor" on gasoline and diesel fuel so that the choice to use a petroleum fuel is never based on a lower price than clean fuel options. This would discourage oil producers from dropping prices to discourage clean fuels investment AND prevent people from paying a financial "penalty" for wanting to help clean our air.