Though CNG produces many advantages, it can’t be denied that it also has its drawbacks. There are several disadvantages related to CNG such as the lack of fueling stations within regions. There are close to 120,000 natural gas vehicles in the United States and around 150,000 NGVs being used on the road; the most of them consisting of trucks. Altogether, there are about 10 million natural gas powered vehicles in the world. To cater for this need, it is estimated that there are only about 1,500 natural gas fueling stations on a national scale in the US. Only about half of these stations are made open to the public. In contrast, there are more than 190,000 gasoline stations in the US. Many vehicle owners are reluctant to switch to CNG as an alternative fuel because of the difficulty to refuel if they drive to locations that are not equipped with CNG stations. Car users find it more convenient to utilize petrol as their source of fuel as it is easily accessible everywhere. This short of fueling infrastructures has led many parties to turn down CNG as their main fuel for their vehicles. If the use of CNG increases, it is still questionable whether the infrastructure can be developed at a matching pace worldwide, considering the cost to be incurred.
Besides the fact that fuel stations are rather limited, vehicle owners have doubts about the usage of CNG for their vehicles. This is because CNG vehicles presently own a lesser range compared to gasoline powered vehicles. An energy gallon equivalent of natural gas, whether compressed natural gas or liquid natural gas, contains less energy, if measured up against a volumetric gallon of petrol or diesel fuel. It is said that compressed natural gas needs to be keep at extremely high pressure, close to 4,000 pounds per square inch, to attain satisfactory driving range. Attempts have been made by liquefied natural gas to rectify this problem but it requires special storage equipment on-board. This is very troublesome and will also bring about additional cost. Considering this, vehicles running on natural gas are not as good as their gasoline counterparts when it comes to travelling long distance. The lesser driving range offered by CNG powered vehicles once again cause consumers to have a better preference for cars using gasoline.
It must also be noted that vehicles operating on CNG cost more than vehicles running on gasoline. This is because natural gas vehicles have to be installed with additional components for the storage of fuel, which is more costly than gasoline tanks. For example, the Honda Civic Sedan that consumes gasoline costs around $22,255 in the United States. On the other hand, the Honda Civic GX, which is a natural gas consumer car, is priced at $24,590. While the cars running on petrol are much cheaper and can be purchased everywhere, natural gas vehicles are sold in selected places such as California and New York. Besides, gasoline fueled vehicles come in a variety of specifications which could travel a longer distance compared to natural gas vehicles. Consumers today have very high demands about their purchases and style of living, and they go for the best of both worlds in order to gain value for their money. Vehicle owners want to have choices when it comes to the type of car, design and suitability to meet their needs in addition to the ability to travel long distance, for a lower price tag. This is where gasoline consuming vehicles have the upper hand and CNG powered vehicles fail to provide.
In addition, gasoline powered vehicles could also be converted to CNG. The conversions of gasoline powered vehicles to use CNG are expensive and time consuming. Natural gas vehicles which have been specially manufactured in factories are designed in such a way to increase the efficiency of natural gas uses. Conversion is therefore a drawback because these vehicles are designed to take advantage of the higher octane of CNG which results in better engine competence. Many of the CNG powered vehicles today are vehicles that were originally gasoline powered. These vehicles have been modified to be bi-fueled, which allows both gasoline and natural gas consumption. Conversions are known for using its existing engine on the contrary to factory produced CNG vehicles. Although the conversions let vehicles users have more flexibility in choosing either gasoline or natural gas, the process of modification is costly and decreases efficiency.
Furthermore, the switching of gasoline powered vehicles to CNG would significantly add to the quantity of natural gas consumed in the region. The United States of America is currently very dependent upon natural gas for the use of electricity. If more vehicles owners convert their gasoline vehicles to compressed natural gas, or if more natural gas vehicles are produced, this will directly cause an upward trend in the consumption of CNG. This is where natural gas will be needed in high demand to supply both electricity as well as fuel for vehicles. The other alternative for electricity is wind power, but it is believed to be undependable as it needs to be backed up by conventional facilities. Natural gas is known to be the most general backing for wind turbines. As it is well known in the theory of economics, an increase in demand will cause a rise in price. If the demand for CNG increases and its supply is unable to follow suit at an equal or higher rate, this will translate into an increase in utility bills. Then, although CNG is currently cheaper than gasoline, the usage of CNG overall may actually become more expensive to the consumer.
Apart from that, CNG fuel tanks are very bulky, and they are said to be about half-inch thick aluminum covered with shatterproof fiberglass. CNG vehicles are much heavier and larger if they were to be compared to a conventional gasoline tank. They are also more cumbersome to install when measured up to Liquefied Petroleum Gas tanks which are immense. This is predominantly a disadvantage to smaller vehicles because a fuel tank in CNG vehicles takes up ample of space. For instance, a fuel tank in a CNG vehicle such as Nazaria could take up plenty of trunk space to a point where there is only enough space for two small suitcases. The same applies to a NGV model of the Honda Civic. Vehicle owners who have families will view this as a huge shortcoming, especially during times of travelling for longer distances in festive seasons, where trunk space for luggage and storage is essential. This disadvantage therefore causes inconvenience for CNG vehicles users.
Though CNG produces various weaknesses, it is still widely used on a national scale. It is still uncertain if there would be any considerable increase in the usage of natural gas to power more vehicles. Many parties involved have generally not been able to prove the efficiency of CNG which often resulted in unintentional consequences. Therefore, more research has to be done in terms to find a better and suitable alternative if CNG was to be replaced. However, considering the ever increasing price of gasoline and its benefits to the environment, compressed natural gas seems to be the alternative fuel for the future and is expected to be around.