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The equipment for collecting dilute exhaust samples involves the use of bag materials (i.e., Tedlar®) that emit hydrocarbons that contaminate samples. This study identifies a list of materials and treatments to produce bags that reduce contamination. Based on the average emission rates, baked Tedlar®, Capran® treated with alumina deposition, supercritical CO2 extracted Kynar® and supercritical CO2 extracted Teflon NXT are capable of achieving the target hydrocarbon emission rate of less than 15 ppbC per 30 minutes. CO2 permeation tests were also performed. Tedlar, Capran, Kynar and Teflon NXT showed comparable average permeation rates. Based on the criteria of HC emission performance, changes in measured CO2 concentration, ease of sealing, and ease of surface treatment, none of the four materials could be distinguished from one another.

FTP-UDDS (urban dynamometer driving schedule) exhaust particulate matter (PM) emission rates were determined for 361 light-duty gasoline (LDGV) and 49 diesel passenger vehicles ranging in model year (MY) from 1965 to 1997. LDGVs were recruited into four MY categories. In addition, special effort was made to recruit LDGVs with visible smoke emissions, since these vehicles may be significant contributors to the mobile source PM emission inventory. Both light and heavy-duty diesels where included in the passenger diesel test fleet, which was insufficient in size to separate into the same MY categories as the LDGVs. Vehicles were tested as-received in three areas: Denver, Colorado; San Antonio, Texas; and the South Coast Air Quality Management District, California. The average PM emission rates were 3.3, 79.9, 384 and 558 mg/mi for 1991-97 MY LDGVs, pre-1981 LDGVs, smoking LDGVs and the diesel vehicles, respectively.

A 1993 Ford Taurus Flexible Fuel Vehicle (FFV) designed to operate on gasoline or methanol has been modified to run on Ed85 (85 vol.% denatured ethanol, 15 vol.% gasoline) and has demonstrated the ability to meet California's Ultra-Low Emissions Vehicle (ULEV) standards. The vehicle maintains the excellent driveability with potentially increased performance and similar efficiency to the baseline vehicle. Using standard twin OEM catalysts, FTP-75 emissions were 0.085 g/mi NOx, 0.88 g/mi CO, and 0.039 g/mi reactivity-adjusted NMOG. Using close-coupled catalysts upstream of the OEM catalysts, FTP-75 emissions were 0.031 g/mi NOx, 0.297 g/mi CO, and 0.015 g/mi reactivity-adjusted NMOG. The catalysts were aged to about 4,000 miles of equivalent use. These emissions compare with ULEV standards of 0.2 g/mi NOx, 1.7 g/mi CO, and 0.04 g/mi NMOG at 50,000 miles of use.

Particulate and regulated gaseous emissions were characterized in a feasibility study for a 1994 Ford Taurus Flexible Fuel Vehicle (FFV) operating on five fuels. The five fuels included Federal Reformulated Gasoline (RFG); 85% fuel grade methanol and 15% gasoline (M85); 85% denatured ethanol and 15% gasoline (E85d); liquefied petroleum gas (LPG) meeting HD-5 specifications; and industry average compressed natural gas (CNG). The vehicle was operated fuel-rich to simulate a vehicle operating condition leading to increased production of particulate matter. This simulation was accomplished by using a universal exhaust gas oxygen sensor (UEGO) in connection with an external controller. Appropriate aftermarket conversion kits involving closed-loop control and adaptive learning capabilities allowed operation on the gaseous fuels. Particulate emissions were characterized by total mass and particle size.

Regulated and volatile organic exhaust species were characterized from a 1993 Chevrolet Lumina operating on CNG, LPG, and reformulated gasoline. For the gaseous fuels, aftermarket conversion kits were installed on the vehicle, and the resulting exhaust emissions were compared to the gasoline baseline results. For all of the fuels, the vehicle was operated over the chassis dynamometer portion of the Federal Test Procedure for light-duty vehicles at fuel/air equivalence ratios of 0.8, 1.0, and 1.2; and exhaust emissions were sampled both with and without the catalytic converter in place. Analyses of exhaust samples included determination of regulated exhaust emissions by CFR methods, hydrocarbon speciation and aldehyde and ketone analyses according to Auto/Oil Phase II methods, and the determination of trace exhaust species by mass spectral analysis methods.

A Remote Sensing Device (RSD) was used to measure on-road emissions of carbon monoxide (CO), hydrocarbons (HC, propane equivalent), and carbon dioxide (CO2) from vehicles as they entered and exited a centralized Arizona Inspection and Maintenance (I/M) lane conducting a steady-state dynamometer test. Approximately 16,000 RSD measurements were collected and matched with I/M records from 9,000 vehicles. The RSD demonstrated approximately a 90 percent success rate in recording emissions and license plates. When moderate RSD pass/fail standards were applied to the data, approximately 41 percent of the 1981 and later I/M failures were identified based on a single RSD measurement. When the minimum reading from two RSD tests was used, only 20 percent of the I/M failures were identified. However, virtually all of the vehicles that failed two RSD tests were I/M failures.