MTBE is made from methanol, which is usually made from natural gas. The fact that California is nearly 100 percent dependent on petroleum for transportation could cause a serious problem, like it did in 1973 and 1979 when the gas supply was limited and the prices went up. California's dependence on petroleum makes us vulnerable to price and supply disruptions. Air quality concerns have increased the importance of alternative fuels and advanced transportation technologies like electric vehicles. By increasing alternative fuel use, such as natural gas and electricity, consumers have fuel choices that compete with gasoline and diesel, broaden our supply base, and have lower environmental impacts.
Natural gas is the basic energy source for most of the alternatives to petroleum.
On one hand, this is good because most of the natural gas we use comes from friendly North American countries, if not the United States itself. And at the present, there seems to be a plentiful supply of natural gas. So, the supply of natural gas is relatively stable and reliable. On the other hand, natural gas is a non-renewable fossil fuel, just like petroleum and coal, and so, it too will some day be used up if people continue to use a lot of it. Alcohols - ethanol and methanol .