Thomas C. Austin

Development of Improved Loaded-Mode Test Procedures for Inspection and Maintenance Programs

The California Bureau of Automative Repair (BAR) and Sierra Research, Inc. (Sierra) have evaluated a large number of alternative emissions test procedures and developed new procedures that could substantially increase the ability to identify defective vehicles under vehicle inspection and maintenance programs

The California Vehicle Emission Control Program — Past, Present and Future

Although the degree of vehicle and industrial pollution control which has already been achieved in California might have been sufficient to solve the air pollution problems that existed when the program began, further controls of both motor vehicle and industrial sources are still needed. The tremendous growth that has occurred in motor vehicle traffic and industrial sources has substantially reduced the rate of progress toward the achievement of clean air for California. Motor vehicles are projected to remain a very significant contributor to Californias air problems unless further control is achieved. 17 refs.

A comparison of refueling emissions control with Onboard and Stage II Systems

A comparison of alternative methods for the control of motor vehicle refueling emissions indicates that Stage II control systems installed on motor vehicles. In addition, Stage II control can be achieved with a shorter implementation schedule. Because of this advantage, Stage II controls can achieve more than twice the hydrocarabon reductions possible with Onboard systems during the next ten years when additional reductions are needed to meet the ambient air quality standard for ozone.

Development of the IM147: an alternative inspection/maintenance mass-emission transient test to address vehicle preconditioning concerns.

Abstract A series of studies was performed to develop an alternative to the U.S. Environmental Protection Agencys gold standard IM240 mass-based emission test. The new IM147 test was based on the second phase of the IM240 that consists of 147 sec of transient vehicle operation. Paired IM240/ IM147 tests were conducted on vehicles ranging from 1981 to 1996 to determine IM147 cutpoints and excess emissions were identified. Additionally, an optimized test procedure was developed that combined possible triplicate IM147s with improved drive trace quality control, fast-pass, and retest methods. The optimized procedure was found to provide improved vehicle preconditioning with a relatively minor decrease in excess emissions identification. Resulting identification rates ranged from 96 to 100% for hydrocarbons (HC), 93-100% for CO, and 93-100% for NOx, depending on cutpoint selection, while false failures caused by lack of vehicle preconditioning were reduced to essentially zero. Significant vehicle throughput improvements were achieved through the development of software algorithms involving modal fast-pass and retest procedures. Modal drive trace variation limits also were developed to improve test accuracy. The combination of the algorithms reduced average IM147 test times by nearly 60%.

GASOHOL: TECHNICAL, ECONOMIC, OR POLITICAL PANACEA?

A systems analysis of the gasohol production processes indicates that gasohol is increasing rather than decreasing the nations dependence on crude oil. The federal governments claim that gasohol can reduce the nations dependence on imported energy appears to be based principally on political considerations, but also on the assumption that coal will eventually replace the petroleum and natural gas currently used in the gasohol production wherever possible. The authors advocate reevaluation of the governments commitment to gasohol and increased governmental support for using the nonrenewable resources needed for gasohol production on the production of synthetic gasoline and diesel fuel, and methanol, all of which are projected to be less expensive and more energy efficient fuels.

VEHICLE MISFUELING IN CALIFORNIA DURING 1979

A survey of vehicle refueling practices in California during the gasoline shortage of 1979 indicates that the use of leaded gasoline in catalyst equipped vehicles was occurring at a rate of about 1.6%. Based on the effect that leaded fuel has on the exhaust emission characteristics of catalyst equipped vehicles it is estimated that misfueling in California is increasing hydrocarbon and carbon monoxide emissions by about 4% and 1.6%, respectively from late model passenger cars.

A COMPARISON OF PRIVATE GARAGE AND CENTRALIZED I&M PROGRAMS

A comparison of a centralized I&M program and a private garage I&M program currently operating in California indicates that the centralized program is providing over ten times greater emissions reductions. An analysis of the potential for upgrading both programs indicates that the private garage approach is unlikely to ever be competitive with a centralized I&M program.