Search Results

This report presents the Auto/Oil AQIRP results of a methanol fueled vehicle emission study. Nineteen early prototype flexible/variable fueled vehicles (FFV/VFV) were emission tested with industry average gasoline (M0), an 85% methanol-gasoline blend (M85), and a splash-blend of M85 with M0 (gasoline) giving 10% methanol (M10). Vehicle emissions were analyzed for the FTP exhaust emissions, SHED diurnal and hot soak evaporative emissions, and running loss evaporative emissions. Measurements were made for HC, CO and NOx emissions and up to 151 organic emission species, including air toxic components. M0 and M10 emissions were very similar except for elevated M10 evaporative emissions resulting from the high M10 fuel vapor pressure. M85 showed lower exhaust emissions than M0 for NMHC (non-methane hydrocarbon), OMHCE (organic material hydrocarbon equivalent), CO and most species. M85 had higher exhaust emissions for NMOG (non-methane organic gases), NOx, methanol and formaldehyde.

Exhaust and evaporative emissions were measured as a function of gasoline composition and fuel vapor pressure in a fleet of 20 1989 vehicles. Eleven fuels were evaluated; four hydrocarbon only, four splash blended ethanol fuels (10 vol %), two methyl tertiary-butyl ether (MTBE) blends (15 vol %) and one ethyl tertiary-butyl ether (ETBE) blend (17 vol %). Reid vapor pressures were between 7.8 and 9.6 psi. Exhaust emission results indicated that a reduction in fuel Reid vapor pressure of one psi reduced exhaust HC and CO. Adding oxygenates reduced exhaust HC and CO but increased NOx. Results of evaporative emissions tests on nineteen vehicles indicated a reduction in diurnal emissions with reduced Reid vapor pressure in the non-oxygenated and ethanol blended fuels. However, no reduction in diurnal emissions with the MTBE fuel due to Reid vapor pressure reduction was observed. Reducing Reid vapor pressure had no statistically significant effect on hot soak emissions.

The E-35 “Running Loss” program was planned in the fall of 1996, and conducted in the summer of 1997, as the third part of a series of Coordinating Research Council (CRC) sponsored evaporative emission test programs. One hundred and fifty vehicles (half cars - half light duty trucks) were recruited at a local I/M lane, and tested for running loss emissions at the ATL Facility in Mesa, AZ. The previous CRC programs had studied hot soak, and then diurnal emissions. Running loss emissions were measured in a Running Loss SHED (RL-SHED) for a 25 minute, 7.5 mile trip on a hot summer day (95°F). Vehicles from model years 1971 through 1991 were tested. A wide range in emission levels was observed - from a low of 0.13 g/mile to 43 g/mile. The test results were not able to establish whether car emissions are different, or the same, as light duty trucks. The major causes of the high emissions were liquid leaks on carburetor equipped models.