Compressed Natural Gas, otherwise known as (CNG) is a type of fossil fuel that is often used as a substitute for conventional vehicle fuels such as gasoline, propane, and diesel. While CNG still produces a certain amount of greenhouse gases, it is widely regarded as a better environmentally friendly alternative to the other conventional fuels. It is also considered to be quite a bit safer than those fuels in case it is spilled. This is because natural gas is actually lighter than the air and it will disperse at a quick rate once it is released.

CNG is formed when natural gas is compressed to less than one per cent of its volume at standard atmospheric pressure. The gas is housed and distributed via solid containers, which are typically in spherical and cylindrical designs. CNG can be used in traditional gasoline vehicles which have been converted over to bi-fuel vehicles, which combines gasoline and CNG). These types of vehicles are now becoming more popular in South America and Europe because of the rising price of oil and gas. CNG is also becoming a popular fuel for vehicles such as pickup trucks, trains, and buses.

It is estimated that there are about eight million natural gas vehicles on the road throughout the world at present, with the largest usage being in Argentina, Brazil, Pakistan, Italy, India, China, Iran, and Thailand. In fact they are very popular in South America, with that continent being the home to almost half of the vehicles.

The CNG vehicles that are driven in Europe are really considered bi-fuel vehicles. This means they can run on one fuel at a time. The engine is the standard gasoline internal combustion engine and it can operate on either gasoline from the gas tank or the CNG, which is stored in a cylinder in the trunk of the car. All the driver has to do is flip a dashboard switch to alter the type of fuel to burn. There are several auto manufacturers that deal in bi-fuel cars.

Any existing gas vehicle can converted into a combination gasoline/CNG machine. The auto would have to be retrofitted by qualified mechanics. This means a CNG cylinder would be placed in the trunk to store the fuel. The CNG injection system and the electronics would also need to be installed properly.

In the US, the government offers federal tax credits for people who buy a new CNG vehicle. The vehicles are popular in California as several bus fleets are in use as public transportation and there are well over 100 fuelling stations in the state. The gas itself is about 30 to 60 per cent cheaper than gasoline. However, the only CNG car that is currently manufactured in America is the Honda Civic GX sedan. Because it is a much cleaner fuel, U.S. Congress has encouraged people to convert their vehicles to CNG with tax credits of up to 50 per cent of the cost of conversion.

CNG is also being used by several railways and it seems this type of fuel method is gaining popularity very quickly across the world. It should not be too long before more natural gas vehicles are seen on the roads of North America.