Fuel formulation for recent model light duty vehicles in Mexico base on a model for predicting gasoline emissions

Effects of gasoline properties on exhaust and evaporative emissions on light duty vehicles ranging in model year from 2008 to 2010 were tested on a chassis dynamometer over the US FTP-75 driving cycle. Tailpipe emissions were characterized for criteria pollutants (CO, NOX, NMHC, and NMOG), and a suite of unregulated emissions including important air toxics, carbonyls, and ozone reactivity. Measurements were performed under three different driving conditions, i.e. cold transient, stabilized and hot transient. These three driving conditions were simulated using the US FTP-75 driving cycle. Hot soak and diurnal evaporative emissions were quantified and characterized for NMHC. The fuel quality parameters investigated include RVP, oxygen, olefins, aromatics, distillation parameters and sulfur in the range from 5 to 19 ppm. The results of the study were used to update a previous statistical model developed for predicting emissions based on fuel quality. The procedures and statistical methods employed to develop the predictive model for this test program were similar to those used to construct the United States Complex models for regulated and toxics emissions. The predictive model allows refineries to optimized gasoline compositions providing they can show that certain emission outcomes (as prescribed by regulation) will be achieved.