The emissions are measured in accordance with SAE Recommended practices J177, J215, and J244 using nondispersive infrared equipment for CO and CO2, a heated flame ionization analyzer for HC, and a high performance NDIR or a chemiluminescence analyzer for NOx. All emissions are measured during steady-state engine operation. The mass rate of emissions is calculated (a) from the concentration in the exhaust gas and the exhaust flow for each mode or (b) alternately, using a carbon balance method, from the concentration in the exhaust gas and the mass flow rate of fuel for each mode. If method (a) is used, CO₂ should be measured for data validation. The final emissions are calculated by dividing the summation of the weighted emission mass rates by the summation of the weighted brake power values for a cycle.