The impacts of fuel consumption by light-duty vehicles are profound, influencing economic prosperity, national security, and Earth’s environment. Increasing energy efficiency has been a continuing and central objective for automobile manufacturers and regulators pursuing objectives that range from reducing vehicle operating costs and improving performance to reducing dependence on petroleum and limiting greenhouse gas emissions. Given heightened concerns about the dangers of global climate change, the needs for energy security, and the volatility of world oil prices, attention has again been focused on reducing the fuel consumption of light-duty vehicles. A wide array of technologies and approaches exist for reducing fuel consumption. These improvements range from relatively minor changes with low costs and small fuel consumption.
