Evaporative Emissions—Which Volatility Factors Count?

Several volatility parameters have been investigated in an experimental study of volatility/emission relationships. These volatility indexes include Reid vapor pressure and several distillation properties. The experimental data show that the fuel tank losses are related characteristically to one parameter while carburetor losses appear to be related to a different parameter. The effect of volatility upon exhaust emissions was investigated in connection with the evaporative loss studies, and it appears that these emissions also are related directly or indirectly to the volatility characteristics of the gasoline.

The experimental results are used to illustrate how the several losses are related to the respective volatility parameters.