Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles evaluates various technologies and methods that could improve the fuel economy of medium- and heavy-duty vehicles, such as tractor-trailers, transit buses, and work trucks. The book also recommends approaches that federal agencies could use to regulate these vehicles' fuel consumption. Currently there are no fuel consumption standards for such vehicles, which account for about 26 percent of the transportation fuel used in the U.S. The miles-per-gallon measure used to regulate the fuel economy of passenger cars. is not appropriate for medium- and heavy-duty vehicles, which are designed above all to carry loads efficiently. Instead, any regulation of medium- and heavy-duty vehicles should use a metric that reflects the efficiency with which a vehicle moves goods or passengers, such as gallons per ton-mile, a unit that reflects the amount of fuel a vehicle would use to carry a ton of goods one mile. This is called load-specific fuel consumption (LSFC). The book estimates the improvements that various technologies could achieve over the next decade in seven vehicle types. For example, using advanced diesel engines in tractor-trailers could lower their fuel consumption by up to 20 percent by 2020, and improved aerodynamics could yield an 11 percent reduction. Hybrid powertrains could lower the fuel consumption of vehicles that stop frequently, such as garbage trucks and transit buses, by as much 35 percent in the same time frame.

For a century, almost all light-duty vehicles (LDVs) have been powered by internal combustion engines operating on petroleum fuels. Energy security concerns about petroleum imports and the effect of greenhouse gas (GHG) emissions on global climate are driving interest in alternatives. Transitions to Alternative Vehicles and Fuels assesses the potential for reducing petroleum consumption and GHG emissions by 80 percent across the U.S. LDV fleet by 2050, relative to 2005. This report examines the current capability and estimated future performance and costs for each vehicle type and non-petroleum-based fuel technology as options that could significantly contribute to these goals. By analyzing scenarios that combine various fuel and vehicle pathways, the report also identifies barriers to implementation of these technologies and suggests policies to achieve the desired reductions. Several scenarios are promising, but strong, and effective policies such as research and development, subsidies, energy taxes, or regulations will be necessary to overcome barriers, such as cost and consumer choice.

Various combinations of commercially available technologies could greatly reduce fuel consumption in passenger cars, sport-utility vehicles, minivans, and other light-duty vehicles without compromising vehicle performance or safety. Assessment of Technologies for Improving Light Duty Vehicle Fuel Economy estimates the potential fuel savings and costs to consumers of available technology combinations for three types of engines: spark-ignition gasoline, compression-ignition diesel, and hybrid. According to its estimates, adopting the full combination of improved technologies in medium and large cars and pickup trucks with spark-ignition engines could reduce fuel consumption by 29 percent at an additional cost of $2,200 to the consumer. Replacing spark-ignition engines with diesel engines and components would yield fuel savings of about 37 percent at an added cost of approximately $5,900 per vehicle, and replacing spark-ignition engines with hybrid engines and components would reduce fuel consumption by 43 percent at an increase of $6,000 per vehicle. The book focuses on fuel consumption-the amount of fuel consumed in a given driving distance-because energy savings are directly related to the amount of fuel used. In contrast, fuel economy measures how far a vehicle will travel with a gallon of fuel. Because fuel consumption data indicate money saved on fuel purchases and reductions in carbon dioxide emissions, the book finds that vehicle stickers should provide consumers with fuel consumption data in addition to fuel economy information.

This volume presents realistic estimates for the level of fuel economy that is achievable in the next decade for cars and light trucks made in the United States and Canada. A source of objective and comprehensive information on the topic, this book takes into account real-world factors such as the financial conditions in the automotive industry, costs and benefits to consumers, and marketability of high-efficiency vehicles. The committee is composed of experts from the fields of science, technology, finance, and regulation and offers practical evaluations of technological improvements that could contribute to increased fuel efficiency. The volume also examines potential barriers to improvement, such as high production costs, regulations on safety and emissions, and consumer preferences. This practical book is of considerable interest to car and light truck manufacturers, policymakers, federal and state agencies, and the public.

Several Members of Congress and public interest groups have recently proposed policies that would reduce gasoline consumption in the United States. Such proposals stem primarily from a desire to enhance the nation's energy security and to decrease its emissions of carbon dioxide, a key greenhouse gas that affects the Earth's climate. This book compares three methods of reducing gasoline consumption: increasing the corporate average fuel economy (CAFE) standards that govern passenger vehicles, raising the federal tax on gasoline, and setting a limit on carbon emissions from gasoline combustion and requiring gasoline producers to hold allowances for those emissions (a policy known as a cap-and-trade program). Also, the book weighs the relative merits of those policies against several major criteria: whether they would minimise costs to producers and consumers; how reliably they would achieve a given reduction in gasoline use; their implications for automobile safety; and their effects on such factors as traffic congestion, requirements for highway construction, and emissions of air pollutants other than carbon dioxide. In addition, the book examines two more policy implications that lawmakers may be concerned about: the impact on people at different income levels and in different regions, and the effects on federal revenue.