A Preliminary Report on Natural Gas Fueled Truck Emissions

The emission characteristics of a fleet of five dual fueled trucks are reported. Detailed emission data of CO, THC and NO_x are presented at various modes of operation. In most cases, the CO and NO_x concentrations are lower for engines using compressed natural gas. The THC emission is lower for engines fueled with gasoline. The concentration of all emitted species increases with truck mileage driven. The catalytic converter is less effective for natural gas operation.