With significant changes in world economy and rapid fluctuations in global climate over the past few years, people are now becoming more and more conscious about using the expensive and scarce conventional sources of energy, like gas and petroleum, to fuel their automobiles. The necessity for alternative fuels that are cleaner, renewable, cheaper, and eco-friendly is now being felt worldwide. Also, many nations are now investing millions of dollars to encourage the research and use of such fuels to decrease their dependence on the Middle East countries for petroleum.

The most effective and preferred alternative fuels for cars and other vehicles include propane, bio-diesel, methanol, ethanol, and electricity. Propane, the main ingredient of LPG (Liquid Petroleum Gas), can be used as an effective automobile fuel as it not only releases less toxic pollutants in the atmosphere, but also brings about a two-fold increase in the longevity, engine stability, and performance of the car. LPG is produced as a by-product of the petroleum refining process and is therefore much cheaper than petrol.

Another fuel that can be taken into consideration as an alternative to petrol is bio-diesel.

It is produced by processing vegetable and plant waste. It exhibits all the properties of synthetic diesel and is highly cost-effective. It also does not cause any kind of environmental pollution. Similarly two important alcohol fuels, namely ethanol and methanol, can be used to replace petrol. Electricity is also being used currently to fuel battery powered electric cars. However, it may not be an ideal solution as many nations of the world still have shortage of electricity. There are several other cleaner fuels that can be used to run automobiles and replace petroleum and gas in near future.

Nonetheless, each of these alternative car fuels has its own advantages and disadvantages, which should be analyzed in great detail before putting it to practical use.