Many of you would say that a cars' fuel efficiency is nothing new. The cars currently available (passenger-cars with gasoline engines) run 12.3 kilometers per liter on the average (for 10.15 mode, 1993), which is 2.9 kilometers per eu in an Ecological Unit. In reality, fuel efficiency tends to be less than that in theory and is assumed to be about 2.5 kilometers per eu.

In the late 1970s, Japanese car manufacturers struggled to develop fuel efficient cars in order to meet the emission control requirements stipulated by Muskie Act of the United States. Such efforts led to improvements in fuel efficiency and the quality of cars, making the Japanese automobiles highly competitive around the world. This is still talked as a good example, for it shows that environmental measures do not necessarily suppress economic growth .

Now, a question. Are the Japanese cars really fuel efficient? The actual energy required for a car to transport passengers is 572 kcal per passenger and kilometer (which is, in terms of gasoline, equivalent to about 15 kilometers per liter). This is four times higher than the energy required by a bus and twelve times that of a railway. Let's consider the reasons why the fuel efficiency of cars remains unimproved and what can be done about that.

1. Roads Being Congested
   
   This is the reason why the Japanese Government directs most of its expenditure for global warming measures into road construction, which is considered to be effective in helping the problem of traffic congestion. Road improvement could certainly be a help if it does not create more traffic. But in reality, it does. Thus, the problem of congestion is likely to remain unsolved as long as such a vicious cycle continues.
   
   Many countries are taking measures to reduce traffic. For example, in Mexico City, the authorities are testing a pilot traffic control scheme under which cars with only either odd or even license plate numbers are allowed in the city center at a particular time. In Germany, the government is carrying out a policy of reassessing railways and encouraging car passengers to switch to railways by introducing substantial cuts in the railway pass rates. In Japan, too, the "Park & Ride" campaign is being put to a test in Kamakura. This was designed to encourage car passengers who wish to travel into the city center to park their cars in the car parks just outside the city center and then switch to a railway or a bus. In addition, traffic information will soon be made available through car navigation systems. Every Japanese car manufacturer appears to be working out a plan for a future transportation system which makes automatic driving feasible.
   
   
2. Most Cars Carry Only One Passenger
   
   Most cars carry only one or two passengers, although they can carry up to four . There is no wonder why fuel efficiency remains unimproved if we run a lump of iron weighing about 1.5 tons just to transport one passenger, who weighs only about 70 kilograms. In Singapore, there are restrictions on the free entry to the city center by one- passenger cars, while Los Angeles has secured a traffic lane for cars carrying more than one passenger. The issue of the one-passenger car can be really thorny, as it concerns a charm inherent to cars - that is to say, a person can hop in it and go off whenever he or she likes.
   
   
   
3. Actual Fuel Efficiency Is Falling
   
   The Fuel efficiency of Japanese cars peaked in 1998, followed by a continual decline due to increasing consumer tastes for big and expensive cars, as well as the car weight increase incurred by the obligatory installment of safety equipment. Furthermore and ironically, recreational vehicles, which have a high displacement volume and consume more fuel, continue to be selling well compared to fuel efficient cars for which considerable development efforts were made. It can be assumed that whether fuel efficiency improves or not depends on consumer awareness. In the meantime, it is necessary to provide an incentive for consumers who choose fuel efficient cars, by taking some measures like the introduction of carbon tax, and so on
   

The State of California in the United States instituted a regulation concerning zero emission vehicles (which emit no fumes) and low emission vehicles (which emit less toxic fumes). The regulation stipulates that a certain percentage of vehicles sold in and after the enforcement date must be zero or low emission vehicles. In order to sustain business operations, every car manufacturer around the world is developing low pollution and fuel efficient cars, aiming to satisfy the requirements of the law. In the meantime, car manufacturers are considering possible future measures which might be taken in relation to exhaust fumes and global warming.

The zero emission vehicles currently available consist of "Electric Vehicles" only. It is said that one power station uses zero emission vehicles, while emitting exhaust gas through its operation. However, electric vehicles still have some disadvantages such as long charge hours, driving range and price.

The "Fuel Cell Electric Vehicle", which is now under development by every car manufacturer, generates electricity through a chemical reaction by using hydrogen or ethanol (a reverse reaction of water electrolysis). As fuel cell electric vehicles do not need to be charged, they can be used in the same way as conventional cars. Not only that, but also the only exhaust emission is steam. They are expected to be the favorite among the future vehicles.

Toyota's Prius, a hybrid vehicle which was launched at the end of last year, combines the best of the gasoline-fueled cars and the electric vehicles. It is not a zero emission vehicle as it uses gasoline engine. However, the engine operates only when its burning efficiency is high. While in motion, the electric motor is used as the generator to charge the battery so that it can assist the engine when its burning efficiency gets low. Thus, energy-conservation and low- pollution driving are realized without charging. Prius runs 28 kilometers per liter (10.15 mode), which is as twice the fuel efficiency of other cars of comparable performance. In the Ecological Unit, its fuel efficiency is 6.7 kilometers per eu. The target set by the European car manufacturers, which is 100 kilometers per three liters, is only a step away for it.

It can be said that cars have been the very dream of mankind of the 20th century in which oil civilization has flourished. It seems that we still have a desire to hold onto cars, even if that means most of our income is spent on their loans and maintenance. We just can't give up cars despite the fact that 14,000 deaths were caused annually by traffic accidents in Japan alone and our awareness that cars offer no prospects for improving air pollution.

It is inevitable that petroleum resources will be exhausted in the next century. Unless fuel efficiency improves to the level of 100 kilometers per liter or so, or inexpensive zero emission vehicles are successfully developed, the 21st century can offer no hope for cars. It truly is difficult to give up a dream.