Counting the green miles

Switching to a 'green' automobile is probably the best decision you can take in the interest of the environment. However, you might face a dilemma whether to go for a CNG or LPG-fuelled vehicle. This article should help you decide.

The alarming rate of global warming, combined with the increasing level of pollution, has augmented the demand for green vehicles. If you are an environment-conscious driver, you may be looking for greener options, which can decrease your carbon footprint. While diesel and electric cars are more fuel efficient, they are an expensive option compared to petrol variants. In this context, Liquefied Petroleum Gas (LPG) and Compressed Natural Gas (CNG)-powered vehicles are becoming a popular choice in India.

What is LPG?
LPG is a mixture of hydrocarbons. Its main constituent is propane with a proportion of ethane and butane mixed in. It is one of the few gaseous fuels that can be used in spark-ignition engines. Vehicles fuelled with LPG are one of the most environment-friendly cars available in the market today.

What is CNG?
CNG mainly comprises methane. A CNG conversion kit for an automobile contains a cylinder, vapour bag, high pressure pipe, refueling valve, pressure regulator, selector switch, connectors and gauges. This kit has been approved by the Central Motor Vehicle Rules, 1989.

Difference between LPG and CNG
While both LPG and CNG-fuelled automobiles are a greener option compared to petrol-fuelled ones, there are a few distinct differences between the two. Some of them are highlighted below:

• The most important difference is the fuel storage tank. The storage tank for CNG is heavier and bulkier, while a LPG tank is smaller and more compact
• CNG is lighter than air. Hence, in case of a gas leak from the tank or pipe, it disperses in the atmosphere quickly, which makes it a safer option. LPG, on the other hand, is denser than air and accumulates in one spot, thus making it volatile
• The contaminants released by CNG on combustion are lesser compared to LPG. The main reason for this is that LPG is a combination of gases, whereas CNG comprises only methane

Popularity of both options
Among LPG and CNG-fuelled vehicles, LPG emerges as the more preferred for private use due to its edge over CNG with regards to safety and size. Although a large number of public transportation vehicles in India are CNG-fuelled, refueling stations for the same are less in number. Moreover, CNG cylinders take up a lot of boot space, making LPG a more attractive option for individuals.

From the cost perspective, too, LPG proves superior as the installation cost of a CNG kit is high. As there is a dearth of company-fitted CNG cars in India, many automobile companies have introduced LPG variants. Popular ones among them are Maruti Suzuki WagonR and Omni, Tata Indica V2, Hyundai Santro Xing, Chevrolet Spark, etc.

In today's scenario, it is only a matter of time when the trend changes in favour of green vehicles and newer innovations like electric cars take the lead. Adoption of alternate fuel-powered vehicles is bound to become more popular, making them as prevalent as petrol or diesel car variants. Switching to a LPG or CNG-powered car hence makes sense.