LAUSR

Abstract The transportation sector in Brazil is a significant consumer of energy. This consumption progressed at a regular speed, even though vehicles individually become more efficient. The exergy analysis of societies conventionally consists of a single efficiency value applied to extended periods, and this value is essentially a reproduction of an instant. In this study, the exergy efficiencies are calculated for the Brazilian passenger vehicle fleet from 1970 to 2020 based on a definition of efficiency (ratio of the transport service needed to the fuel exergy consumed), which differs from traditional input/output analysis. To calculate efficiencies, some key vehicle parameters were analyzed, and their evolution was measured over time. Exergy efficiencies were low in the period, between 3.4% and 8.3%, with a recent improvement tendency. Transportation service required fell steadily until around 2010 when the trend was reversed. This formulation of efficiency should improve conventional exergy analysis applied to societies and help understand the administration of vehicle improvement and consumer choice, improving policy motivations for better resource use in the future.