Vehicle Total Life-Cycle Exhaust Emissions

A methodology is established to assess total life-cycle exhaust emissions for light-duty motor vehicles. The focus is to model a vehicle's carbon monoxide (CO), hydrocarbon (HC), and oxides of nitrogen (NOx) exhaust emissions over its lifetime in the state of California. The data used for this analysis is based on California Air Resources Board's (CARB) Light-Duty Vehicle Surveillance Program (LDVSP), series 12, from March 1993 to March 1994. Bag-based emission data of 165 light duty vehicles from model years (MY) 1984 - 1992 driven under the LA4 and Unified Cycles are analyzed. Vehicle exhaust emissions are estimated based on the following operating conditions: hot-stabilized operation, cold and hot starts, enrichment conditions, and emission control device deterioration/malfunctions. Preliminary analysis shows that for an average late MY 80's or early MY 90's light duty vehicle registered in California, tailpipe emissions over its lifetime roughly total 2100 kg for CO, 120 kg for HC, and 190 kg for NOx. These emission levels are equivalent to 16 g/mi for CO, 0.9 g/mi for HC, and 1.4 g/mi for NOx.