The United States has embarked on a unique experiment to improve the quality of air in its major urban areas by altering the composition of fuels for vehicles. This experiment involves close cooperation between government and industry to set air quality standards that will introduce both better fuels and vehicles in a timely and economical fashion. The consequences of these fuel changes will affect the petroleum and chemical industries for all energy products and are discussed. Learn how these factors--air pollution regulations, automobile design, fuel handling and the quality of reformulated gasoline and other fuels--are interrelated.