A new technique for obtaining engine emission flow rate maps has been developed. The maps are based on specific emissions data obtained on a continuous basis over a single EPA-CVS urban driving cycle test. The data are averaged for the various torque-speed ranges of the engine. It has been found that these dynamic average emission flow rate maps, which are functions only of engine torque and speed, allow instantaneous emissions to be fairly accurately predicted. It also appears that the technique might be used advantageously to determine engine calibration parameters.