Fuel taxation is a joke in most countries and the reasons are historical. When gasoline and diesel were the only mass market fuels, taxing by volume (by the liter or the gallon) made sense. The energy content of a liter diesel and a liter gasoline are different but they are not worlds apart. Now that’s different. What should be important is the km (or mile) that can be driven with this, regardless of how much volume it takes. The cleanest technically and economically mature fuel is methane and its liquid embodiment LNG. The current system taxes the cleanest fuel the most and the dirtiest the least. In Austria we had already convinced the government to equalize LNG to CNG as a fuel when it comes to taxation – we need that everywhere.
Several U.S. senators have reintroduced a bill requiring that excise taxes on liquefied natural gas (LNG) for marine transportation on inland waterways be levied at a rate consistent with energy output relative to diesel and gasoline.