With so many countries cutting back on energy use, there are many governments looking for alternative sources of fuel, especially with the rapidly climbing gas prices. The US is working harder than ever to get other sources of power onto the market. Experts say that not only are gas (octane) fuels pollutant, but the supplies buried beneath the earth are dwindling quickly. Now, with the anxiousness of a fuel crunch looming over our heads, America is finally stepping up and trying to find some other way to fuel our mechanical marvels. Here are the top candidates for alternative fuel king.

Bio diesel is the result of the European effort to remove a considerable amount of the polluting attributes of diesel fuel. This has created a 60% reduction in hydrocarbons, a 40% reduction of carbon monoxide, and a 40% reduction in particulates. Bio carbon is produced from raw materials called feedstock. This material absorbs carbon monoxide in an amount equal to the amount the car using the fuel emits. With this new diesel fuel, diesel engines are working at 50% higher fuel efficiency than normal gas powered engines

Ethanol is, by far, the most popular of the alternative fuels. Ethanol has a very down home farm essence to it as it is made from starch producing plants like corn. Yes, corn is the fuel of the future, although some producers prefer sugar to corn in the ethanol making process. Today, most of the information you hear about ethanol is the E85 mixture, which is a mixture of 85% ethanol, and 15% gas. This alternative fuel can only be used in vehicles especially designed for them as well as vehicles that are 22 E85 compatible. Using ethanol can reduce smog production up to 50%, gas can't say that much. Unfortunately, despite E85's smog emission reduction it is still contributing to ozone depletion, although many experts disagree, and still others have no idea how it happens in the first place.

CNG, or Compressed Natural Gas, is another of the top candidates for the king of alternative fuels. In comparison to gas, CNG comes from domestic, not Middle Eastern Reserves, burns cleaner, and is cheaper. Unfortunately, vehicles that run on CNG require some changes which include: storing natural gas in pressurized tanks, burning the CNG with a modified combustion engine, and it is more economical than gas burning engines. Although, CNG cars emit fewer smog emissions than Hybrid cars, they release more greenhouse gases than Hybrid cars as well.

Besides these top 3 candidates for alternative fuel king, there are other less developed methods. There is liquid coal, which will be too costly to use. There is hydrogen fuel, which will also be costly, because hydrogen isn't naturally found. Fuel cell technology, which sounds a lot like Star Trek, is light years away from being developed. As of now, the hybrid vehicle is probably your best bet as far as fuel efficiency, and fuel alternative. Unfortunately, it doesn't cure us of our dependency on gas. The king of alternative fuel may soon be crowned, but that soon is far away.