advanced vehicle technologies The engineering and design processes that lead to vehicles with high energy efficiencies and low emissions; include direct-injection, hybrid electric, fuel cell, and battery-powered electric vehicle systems. alternative transportation fuels Energy sources other than petroleum gasoline and diesel for motor vehicle applications. These fuels can be produced from nonpetroleum sources and may have energy and emission benefits. feedstock stage The first stage of a transportation fuel cycle; the feedstock stage includes fuel feedstock recovery, storage, and transportation. fuel cycle analysis A procedure used to analyze energy use and emissions during the cycle of energy feedstock production and transportation; transportation fuel production, transportation, and distribution; and transportation fuel use in vehicles (also called well-to-wheels analysis). fuel stage The second stage of a transportation fuel cycle; the fuel stage includes fuel production, storage, transportation, and distribution, in addition to activities such as fuel liquefaction and compression for long-distance transportation and onboard vehicle storage. greenhouse gases The by-products of energy use that are believed to have the potential to cause global warming. Although there are many greenhouse gases, the three major greenhouse gases that result from motor vehicle fuel use are carbon dioxide, methane, and nitrous oxide. life cycle analysis The process of evaluating energy use and emissions of a product from ‘‘cradle to grave’’ (including raw material recovery, material fabrication, product manufacture, product use, product recycling, and disposal). This process is typically used for consumer products; fuel cycle analysis (well-to-wheels analysis) is usually used for transportation vehicles/fuels. pump-to-wheels stage The second stage of a well-towheels analysis (also called vehicle operation stage). It begins with refueling of vehicle fuel tanks. Emissions at this stage may come from fuel combustion or conversion, fuel evaporation, and brake and tire wear. vehicle operation stage The last stage of a transportation fuel cycle; this stage begins with refueling of vehicle fuel tanks. Emissions at this stage may come from fuel combustion or conversion, fuel evaporation, and brake and tire wear. well-to-pump stage The first stage of the well-to-wheels analysis (also called the upstream stage), it covers all activities from the wells where fuel feedstock is recovered, to fuels available at the pumps of vehicle refueling stations. In particular, it includes activities associated with the feedstock stage and the fuel stage of a transportation fuel cycle analysis. well-to-wheels analysis Also called a fuel cycle analysis, this process assesses all activities from the wells where fuel feedstock is recovered, to vehicle wheels where useful energy is generated and used to move vehicles. The analysis focuses in particular on energy use and emissions of energy feedstock production and transportation; transportation fuel production, transportation, and distribution; and transportation fuel use in vehicles.