A Life-Cycle Model of an Automobile

The environmental and energy implications of a midsized automobile were assessed by performing a life-cycle inventory analysis that emphasized manufacture and use phases. An Economic Input-Output Life-Cycle Analysis model was used that produces a large array of indicators of the effects of a product or service on the economy and the environment. The analysis corroborates two previous studies that used the conventional life-cycle analysis model developed by the Society for Environmental Toxicology and Chemistry (SETAC) (1, 2) and EPA (3). The use phase is more important than the manufacture and disposal phases in terms of energy use and environmental discharges. Automobile service is comparable to the fuel cycle in terms of discharges of toxic substances. In contrast to a Volkswagen study, tailpipe exhaust and evaporative emissions of hydrocarbons (HC)/volatile organic compounds (VOCs), nitrogen oxides (NOx), and particulate matter are greater than emissions upstream in the fuel cycle. This difference apparently arises from using on-road tailpipe emissions data, rather than emissions data from laboratory tests. The Economic Input-Output model is found useful for quantifying the range of implications of decisions concerning manufacture and use.