Every engine designer or manufacturer today wants to find ways to reduce engine emissions in pursuit of performance enhancement and conformation to emission standards. There are primarily two areas of focus for this pursuit: reduction of engine-out emissions and engine aftertreatment. In this lecture we will discuss the options available in CONVERGE and best practice recommendations to obtain accurate engine-out emissions. Detailed emissions modeling can be quite complex but can yield accurate predictions that match the measured data and trends across different cases. CONVERGE includes two detailed soot models: particulate mimic and particulate size mimic. CONVERGE contains acceleration strategies to make it feasible to account for detailed soot modeling (which includes gas-phase chemistry for its many sub-processes such as formation via precursor-species, coagulation, and oxidation) in engine simulations. In this course, we will also discuss NOx, unburnt HC, and CO formation in IC engines and gas turbines, look at the models available in CONVERGE, and discuss case setup recommendations to obtain accurate predictions.*This lecture does not include hands-on CONVERGE Studio practice.