Introduction
8,970,000. This is the number of cars Toyota sold in 2008 overtaking General Motors for the first time as the number one automaker by a margin of 33 percent. In 1931, GM surpassed Ford to the largest carmaker position according to Bunkley (2009, Business section, para.1). As stated by Jones (2009, para. 4), this was due to the perception that Toyota is a fuel-efficient automaker though the truth in a CNN poll ranks it 10th in terms of mileage per gallon. GM sales dropped most during the fuel crisis when crude oil prices rocketed to a record high of $147.27 in July of the same year. Fuel efficiency is a measure of the process of converting chemical potential energy in fuel into kinetic energy or work. In automobiles, there are no set standards for measuring this. Units such as the amount of fuel per unit distance in liters or distance traveled per unit fuel used in miles per gallon or kilometers per liter are commonly used to determine fuel consumption and fuel economy in cars respectively. Although fuel efficiency is a desirable need to counter the high cost of energy, it is the use of alternative energy that can economically sustain and satisfy the world’s energy demands.
Challenges
As in Easton (2008), the ‘cradle-to-grave’ approach; fuel efficiency approach in automobiles should be analyzed in totality if the environmental aspects of its effects are to be considered. This ranges from the type of fuel used by vehicles and their effects, fuel used by the manufacturing plants, their sources, and production. For instance, a car may run on more efficient ethanol but to come up with this decision, the cost of ethanol, the green plants destroyed during its manufacture, and the environmental impact of the process of manufacturing need to be considered in determining how efficient it is. Another vehicle may also be designed to give out clean water vapor as the waste product, but the kind of fuel it runs on, the workload it can handle, and the cost of keeping it on the road all have to be factored in.
Automobile pollution of the environment
Currently, all automobiles manufactured by automakers pollute the environment to some degree. This is mostly through the emission of carbon dioxide which is the major product of combustion. The amount of emission is directly affected by the type of fuel used and the fuel source. Several common kinds of fuel such as natural gas, bio-fuel, or coal produce various quantities of emissions. A common scientific fact is that a kilogram of carbon in any hydrogen fuel produces about 3.63 of CO2 emissions. The heavier the fuel, the more the amount of carbon dioxide emitted. This, however, is exclusive of emissions created during drilling, refining, pumping, and transporting the fuel before its usage.
The negative effects are experienced locally, regionally, and globally. Apart from carbon dioxide emissions, the cars’ exhaust fumes also contain carbon monoxide and nitrogen dioxide that poison the human respiratory system endangering the health of those who inhale the fumes when vehicles pass by them. Another problem in places with dense automobile populations is acid rain. This forms from the produced gases which are acidic. When it rains, the gases dissolve in rainwater making it acidic hence acid rains which generally affect plant and aquatic life. This leads to a reduction in crop yields in areas where people practice farming. Global warming is the general rise in world temperatures due to the destruction of the Ozone layer that protects the earth from the harmful radiation of the sun by greenhouse gases or chlorofluorocarbons (Houghton, 2004). This has adverse effects such as a rise in sea levels due to ice melts in arctic regions and expansion of deserts among other climatic changes. Carbon dioxide and nitrogen dioxide present in waste fumes produced by vehicles are some of the major greenhouse gases. With over 600,000,000 cars on the roads today according to Elert (2006, para. 1), each contributing small amounts of these gases, the combined effect is significant
Improving efficiency
Increasing efficiency in automobiles, as discussed in this paper should not only focus on how long the distance a car covers per unit amount of fuel but also reduce negative environmental impact. This can be attained through the use of alternative sources of energy, advancement of technology, and improving usage of current fossil fuels that are most common, available, and affordable to many people.
Solar energy
The sun; a yellowish, relatively middle-aged, medium-sized dwarf star is located 93 million miles from the Earth and the sole source of solar energy. It produces heat and light through nuclear fusion which maintains its interior at the temperature of about 27 million degrees Fahrenheit. Solar-powered cars use hundreds of photovoltaic cells which convert sunlight into electricity that drives the cars while some of it is stored as a reserve. Design trade-off exists between the amount of energy used for running the car and that stored: if all the energy is spent in driving and nothing is kept in reserve, the car stops the moment there is no sunshine. On the other hand, if too much is reserved, the engine runs too slowly because of less power (Gordon, 1991).
The source of fuel in solar-powered vehicles is renewable hence no worries over depletion. The vehicles emit no harmful gases making them have no environmental hazards. They also do not enhance the greenhouse effect. No noise pollution occurs as the vehicles are soundless and 100 percent recyclable.
The photovoltaic cells are expensive and the currently available designs are of low efficiency. The cars are also expensive and full-cycle energy use is very high. There is a geographical limit to where the cars can be used depending on the availability of sunshine
Electricity (hydrogen)
Electric cars use different forms of fuel such as fossil fuels, ethanol, and hydrogen. Among these sources of fuel, hydrogen is the most environmentally friendly. Hydrogen, together with oxygen is turned into electrical energy for driving the car through a chemical reaction in a fuel cell releasing pure water.
The fuel cells can be refilled indefinitely and the battery pack gives great acceleration. Hydrogen is generated from the water making it a renewable source of energy. The waste product of the chemical reaction involved is environmentally friendly water. In addition, the car produces no sound thus eliminating noise pollution.
Although the batteries produce a great acceleration, currently, the available ones have a low range of fewer than 100 kilometers. This limits the distance such vehicles can cover. The maximum achievable speed is low; at 110 kilometers per hour. Manufacturing of the electric car’s batteries and their disposal are some of the causes of water and solid-waste pollution. Currently, the available prototypes are expensive to buy and operate.
Bio-fuel (ethanol)
Ethanol is produced through fermentation of sugars extracted from biomass such as corn or by catalytic hydration of ethylene in the laboratory (Gordon 1991). While efficiency in its production has previously been low with net energy gain ranging between 21-34 percent and questionable in terms of economic viability, this has increased steadily in recent years. As a matter of fact, it is estimated that the net gain will rise to 47 percent in the near future; projections that are also made by research work of Graboski (2002). It can be directly pumped into present car engines with very little modification and give a longer mileage per liter than gasoline.
Apart from being renewable, ethanol is a good antiknock fuel. It can also reduce green house effect depending on the crop growing requirements. There is low toxicity while hydrogen emissions are less photo-chemically reactive. Cellulose conversion could also be cost effective in future.
Use of ethanol requires large volumes of crops in order to be produced while current distillation methods are very energy intensive. This also requires large fuel tanks and frequent refueling. When made from crops, there is a limited supply of raw materials and fertilizers could pose a problem to ground water. Ethanol is corrosive, expensive, degrades some elastomers and metals. It also makes vehicles become hard to start in cold environments. The fuel may also be unfeasible to distribute by nationwide pipeline system.
Mass transit
Mass transit is moving of large number of people in a single vehicle. The logic of the idea is that as vehicles pollute the environment, reducing the number of vehicles in the roads reduces the emission hence lessens pollution. It is done through promoting use of public transport and discouraging utilization of private cars. Another way is by governments investing in efficient railway systems that connect cities suburbs, and charging very high packing fees for private cars compared to public transport buses in cities.
This kind of movement reduces total amount of fuel consumed in a particular area which is a great advantage especially if the type of fuel is nonrenewable. Emissions are reduced as exhaust fumes come from few vehicles unlike in a case where several cars emit. Avoiding congestion of cars reduces traffic jams hence easement of pace of traffic movement.
Initial cost of building infrastructure and operation of mass movement is very high. This makes it hard to be implemented in many places. In most cases, they are crowded, uncomfortable, dirty, and unreliable. There is also an inconvenience of being dropped far from destinations as opposed to private means that takes you to the exact location.
Fuel additives
Since it is impractical to move entirely altogether to cleaner burning fuels in the current world situation, continuous efforts are being made to improve the efficiency of gasoline available for use. This involves increasing the distance covered when the same amount is used and reducing emissions of the toxic fumes produced. Reformulating gasoline by altering its chemical structure is one way of achieving this. There is also blending of gasoline with methyl tertiary butyl ether (MTBE) or ethyl tertiary butyl ether (ETBE) both of which are oxygenates.
In both methods, there is no need for modification of the current vehicle engines as they conveniently burn the fuel. Distribution channels like pipelines that are already in place worldwide can be used in distributing the fuel. Reformulated gasoline lower reactive-hydrocarbons and sulphur oxides emissions plus has narrow flammability limits. The oxygenated additives lower carbon monoxide emission and burn more of gasoline efficiently due to increased oxygen presence.
Both methods are nonrenewable, highly toxic and their leakage contaminates water resources. The fuels are also expensive relative to non enriched ordinary gasoline. Reformulated gasoline has very low auto-ignition temperature hence small leaks in air readily catch fire. It is asphyxiant at high temperatures and has very little effect in new cars.
Conclusion
Fuel efficiency in cars can be achieved in several ways some afore mentioned while others entail the users or manufacturers. These include method of car driving, car sizes, weights, body material among others. Environmental pollution is a major threat to the world and nonrenewable sources of energy are continually and exponentially being depleted. The only sustainable solution to getting more efficient cars that prevent the bleak situation is by completely switching to alternative sources of energy a move hampered by economic constraints.
Reference List
Bunkley, N. (2009). Toyota ahead of G.M. in 2008 Sales. The New York Times. Web.
Easton, T. T (2008).Taking sides: clashing views on environmental issues. Michigan: McGraw-Hill.
Glenn, E. (2006). Number of cars. The Physics Factbook. Web.
Gordon, D. (1991). Steering a new course: transportation, energy, and the environment. Washington D.C: Island Press.
Graboski, M. S. (2002). Fossil energy use in the manufacture of corn ethanol. Colorado: National Academy Press.
Houghton, J.T. (2004). Global warming: the complete briefing. Cambridge: Cambridge University Press.
Jones, Benjamin. (2009). Toyota Takes Over the World…But is it a Good Thing? Ecomodder. Web.