Search Results

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.

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.

Particulate and manganese mass emissions have been measured as a function of mileage for four Escort and four Explorer vehicles using 1) MMT (Methylcyclopentadienyl Manganese Tricarbonyl) added to the gasoline at 1/32 g Mn/gal and 2) gasoline without MMT. The MMT was used in half of the fleet starting at 5,000 miles. The vehicles were driven on public roads at an average speed of 54 mph to accumulate mileage. This report describes the particulate and manganese emissions, plus emissions of four air toxics at 5,000, 20,000, 55,000, 85,000 and 105,000 miles. Four non-regulated emissions were measured and their average values for vehicles without MMT were 0.6 mg/mi for formaldehyde, 0.7 mg/mi for 1,3-butadiene, 9 mg/mi for benzene and 12 mg/mi for toluene. Corresponding values for MMT-fueled vehicles were between 1.5 and 2.4 times higher.