This paper analyzes trends in fuel economy (kilometers per liter) of new passenger vehicles in Mexico over a period of 20 years from 1988 to 2008. Results show that in this period, fuel economy of the new passenger vehicle fleet, including multipurpose vehicles (a category similar to sport utility vehicles, SUVs), increased by only 6.3%. A simple Laspeyres index analysis was developed to evaluate both the impact of changes in vehicle sales structure by category and the changes in fuel economy. Results show that increased sales of heavier, multipurpose vehicles in place of subcompact and compact vehicles, impacted negatively on the fleet average fuel economy. If the structure of sales had continued in the same proportions across all categories as in 1988, fuel economy would have increased by 11.0%, instead of the actual 6.3%. This result coincides with trends in other countries. The paper also presents different scenarios of passenger car fuel economy for the year 2020, and its implications for gasoline consumption and CO2 emissions. The results may influence the new passenger vehicle fuel economy standard that is currently under discussion in Mexico. (C) 2011 Elsevier Ltd. All rights reserved.