The world consumption rate of oil is increasing so fast that the supply will not keep pace. During 1977, the world energy consumption exceeded 265 quadrillion BTU s--the equivalent of over 130 million barrels of oil per day. By the year 2000, world energy consumption is expected to more than double. Some time between 1980 and the turn of the century, world oil production will stop growing and slowly begin to shrink. The inescapable conclusion is that petroleum will not be able to maintain its share of the rapidly growing demand for energy.Recognizing that there is a close relationship between energy consumption and the performance of national economies, especially in industrialized nations, other fuels will be needed to meet growth demands. The world must shift from a predominantly petroleum-based economy to one which will phase in other energy sources, with increased emphasis on coal and nuclear power.This transition will require some complex decisions. Nations will have to choose more sparingly among alternative uses of the limited supplies of petroleum. One of the uses will be for commercial vehicles. However, the limited supplies and continuing higher prices will necessarily result in more fuel-efficient vehicles, more sophisticated bulk quantity delivery systems, and more consolidated production-delivery-marketing networks.