Ammonia exhaust emissions from spark ignition vehicles over the New European Driving Cycle

Nine modern light duty vehicles tested over the New European Driving Cycle showed that ammonia emissions are considerable for gasoline and ethanol flexi-fuel vehicles and also for one diesel vehicle equipped with a selective catalytic reduction system, ranging from 4 mg/km to 70 mg/km. Real-time ammonia emission profiles were monitored at the tailpipe by a High Resolution Fourier Transform Infrared spectrometer during tests at 22 and/or −7 °C. Ammonia emissions are thoroughly discussed and compared to those of its precursors, CO and NO, and other regulated compounds.