Are natural gas cars a real alternative?

There are currently more than 20 million vehicles in the world running on natural gas.
This gas, which is called CNG (Compressed Natural Gas), is the same as the gas used to heat our houses. Natural gas is a resource that is very widely available in the world and is less polluting than petrol or diesel.

In Belgium, around a 4500 cars run already on CNG. A number of manufacturers are stressing this technology, which they consider more promising than electric cars. What’s more, the first CNG pumps have appeared in a few of the country’s service stations.

Differences between CNG and LPG

CNG is our ordinary gas, the gas we use for heating. It is compressed between 200 and 300 bars and consists mainly of methane, whereas LPG (Liquid Petroleum Gas) is a blend of propane and butane compressed between 5 and 7 bars. These differences mean that pressurised CNG can be stored as a gas at ambient temperatures. Moreover, unlike LPG, CNG is lighter than air. So vehicles that use this gas are not subject to the ban on access to underground car parks.

Stored in bottles built into the floor of a car, CNG can be used as a fuel for any vehicle fitted with an internal combustion engine thanks to a simple but costly installation (from € 2,000 to € 4,000 depending on the car model).

Find here all car models running on CNG (in French)

The advantages of CNG compared with diesel or petrol:

• 95 % reduction in fine particle emissions
• 30 % reduction in CO₂ emissions
• 10 tot 12% lower price than diesel
• up to 30% cheaper than petrol
• as quick to fill up as with conventional fuels, which is a plus compared with the recharging time for electric vehicles
• CNG lessens the wear and tear on engines because it produces less combustion residue
• a CNG vehicle can also run on biogas, obtained from the decomposition of organic waste, which increases the environmental benefit.

Calculate your benefits (in French)

The disadvantages of CNG?

• the CNG takes up more space and is heavier than the LPG tank
• CNG costs about twice as much as LPG 
• the limited number of services stations that provide CNG: there are about twelve stations equipped for this purpose in Flanders and about ten that are planning to do so, including in Wallonia
• requires a simple but costly installation.

These disadvantages, which are currently far from negligible, mean that as things stand, not many drivers are convinced by the use of CNG.

However, captive fleets of vehicles (taxis, buses) are already showing an interest in gas. In fact, these vehicles do not need an extensive distribution network and can fill up using a gas supply point fitted with an adapted compressor. In an urban context such as Brussels, the use of CNG could be advantageous for health and prove a significant social gain. So it’s worth keeping an eye on developments.

(See also: 'What different types of electric car are available?')