Recent developments in systematically reduced chemical kinetics are applied to computation of the production of oxides of nitrogen by considering the flame-structure limit of slow CO oxidation along with the thermal mechanism of NO formation. Fuel consumption is presumed to be controlled by turbulent mixing so that the results are applicable to general hydrocarbon fuels. The approach is free of empirical modeling coefficients and relates the rates to elementary chemical-kinetic parameters. Reasonable predictions of motor emissions are obtained when comparisons are made with results of experiments on a dual-fuel diesel engine.