This paper aims to inform the next phase of PROCONVE for LD vehicles by assessing important components of PROCONVE L6 and their relative strengths and weaknesses compared with similar programs in the United States and the European Union. The U.S. and EU programs were selected for this comparison because they have progressed furthest in controlling emissions from motor vehicles, and are often models for other countries implementing vehicle emission control programs.
This comparison highlights a number of areas in which the Brazilian program can be improved upon. A key insight that emerges from this comparison relates to the evolution of PROCONVE relative to the development of U.S. and EU regulatory programs. In Brazil, the stringency of successive stages of PROCONVE has been increased largely through the adoption of more stringent emission limits. In contrast, U.S. and EU programs have developed through the implementation of advanced certification test procedures and specifications in addition to more stringent emission limits. Some of these changes have been highlighted in this paper, and include longer vehicle useful lifetimes, drive cycles covering a broader range of expected operating conditions, real-world driving test requirements, and more challenging evaporative emission testing. These improvements to U.S. and EU programs serve to enhance the representativeness of the vehicle certification process and lead to more effective control of real-world emissions from LD vehicles. Table ES1 highlights the areas where PROCONVE L6 lags behind international best practices, along with potential improvements to be considered for the next phase of PROCONVE L7.
** This paper has been revised from the April 2017 version to clarify ambiguities in the discussion of regulatory requirements and control strategies for evaporative and refueling emissions.