subject: Fuel Efficient Cars [print this page] The term Fuel efficiency refers to a form of thermal efficiency of a process by which chemical potential energy contained in a carrier fuel is converted into kinetic energy. In the context of transport, Fuel efficiency of a particular vehicle refers to the energy efficiency of a specific vehicle model. Fuel efficiency has a direct impact on the carbon emissions that cause pollution and can lead to climate change. However, this is closely associated with the source of fuel that is used to drive a particular vehicle. For example, cars can operate on a number of fuel types such as gasoline, natural gas, LPG, biofuel or electricity and this could result in varying quantities of atmospheric pollution.
It has been found that European-built cars are more fuel-efficient when compared to American vehicles. Although Europe produces lots of higher efficiency diesel cars, gasoline vehicles are also more fuel-efficient. According to a CSI study, most of the European vehicles run on diesel engines, which have greater fuel efficiency than gas engines. While diesel engines have an energy efficiency of 45%, petrol engines have an efficiency of 30%. This is one of the important reasons why diesel cars have better fuel efficiency than petrol cars. Hybrid vehicles are also more efficient than conventional vehicles. Hybrid vehicles operate using smaller combustion engines as electric generators to produce greater range of per unit fuel, thus resulting in significantly less fuel emissions than a conventional vehicle of similar size and capacity.
Hydrogen cars may become commercially available in the future. Hydrogen cars would be powered by either of the two methods : through chemical reactions in a fuel cell that generate electricity to drive electrical motors very efficiently or by directly burning hydrogen in a combustion engine. Hydrogen vehicles could contribute in minimizing atmospheric pollution to a great extent, provided the hydrogen is created by the process of electrolysis using electricity generated from various non-polluting sources such as solar, wind, or hydroelectricity. One of the foremost advantages of fuel cell vehicles is that they can electrolyse water using their own fuel cells, operating in exactly the same way as a rechargeable electric battery.
