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A vehicle emissions round robin test program was conducted using a methanol-fueled vehicle operating on M85. Each of 16 participants conducted two to six Federal Test Procedure (FTP) emissions tests. All participants measured emission rates of hydrocarbon (HC), CO, NOx, methanol, formaldehyde, and acetaldehyde. One participant, designated as a reference lab, conducted emissions testing at the beginning, the end, and two intermediate times during the round robin. Results of the reference lab demonstrated that no significant drift in emissions levels occurred during the 2-year program. Relative lab-to-lab variability for FTP-composite emissions was lowest for NOx, with a coefficient of variation (C.V.) of 12%. CO variability was 16%, HC variabilities (by GC and bench FID) were 17 and 35%, respectively. Methanol, formaldehyde, and acetaldehyde were found to have variabilities of 34, 17, and 63%, respectively.

A study was carried out to increase our understanding of the emissions of air toxics from normal and high-emitting vehicles. This study is part of a larger study on fuel effects in high-emitting vehicles, and is part of the Auto/Oil Air Quality Improvement Research Program (AQIRP). Detailed measurements were carried out on the emissions of two vehicles run on industry-average gasoline. The two vehicles, having similar emissions control technologies, represent a high-emitting vehicle and a normal-emitting vehicle. In addition to the regulated emissions (HC, CO, and NOx), a detailed chemical analysis was carried out on the gas - and particle-phase non-regulated emissions. The vehicles were tested over the U.S. EPA UDDS driving schedule. The high emitter was highly variable with regard to emissions, but always operated rich of the stoichiometric point. Up to 46% of fuel carbon was emitted as CO and unburned HC for the high emitter, compared to less than 1.4% for the normal emitter.

A 1990 Ford Taurus operated on reformulated gasoline was tested under three modes of malfunction: disabled heated exhaust gas oxygen (HEGO) sensor, inactive catalytic converter, and controlled misfire. The vehicle was run for four U.S. EPA UDDS driving schedule (FTP-75) tests at each of the malfunction conditions, as well as under normal operating conditions. An extensive set of emissions data were collected. In addition to the regulated emissions (HC, CO, and NOx), a detailed chemical analysis was carried out to determine the gas- and particle-phase non-regulated emissions. The effect of vehicle malfunction on gas phase emissions was significantly greater than it was on particle phase emissions. For example, CO emissions ranged from 2.57 g/mi (normal operation) to 34.77 g/mi (disable HEGO). Total HCs varied from 0.22 g/mi (normal operation) to 2.21 g/mi (blank catalyst). Emissions of air toxics (1,3-butadiene, benzene, acetaldehyde, and formaldehyde) were also significantly effected.