Unregulated Emissions from Diesels used in Trucks and Buses

A wide variety of exhaust emissions are reported for three diesel engines typically used in heavy-duty intercity truck and intracity bus operation. Particulate, odor, sulfate, sulfur dioxide, and selected non-reactive hydrocarbons were measured in addition to the regulated pollutants from Detroit Diesel 6V-7l and 8V-7lTA engines and a turbocharged Cummins 855 cu in research engine. The 855-TC engine was run in standard and a variable injection timing configuration, while the 6V-7l city bus engine was run with two types of injector designs. Emission rates are summarized in terms of grams per unit of fuel consumed and per unit of power output. The data allows direct comparison between engines and engine configurations, as well as a function of engine speed and load condition.