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Four metrics related to vehicle duty cycle are derived from the energy equation of vehicle motion. Three key application areas are introduced. The first is the ability to quantify the sameness between vehicle duty cycles and the ability to asses a duty cycle's suitability for hybrid vehicle usage. The second area of application allows for the estimation of fuel consumption for a given vehicle over a target duty cycle. The third area of application allows us to predict how non-propulsion fuel use will affect energy use. The paper ends with real-world examples involving actual heavy-duty hybrids.

The National Renewable Energy Laboratory (NREL) has conducted a series of chassis dynamometer and road tests on the 2000 model-year Honda Insight. This paper will focus on results from the testing, how the results have been applied to NREL's Advanced Vehicle Simulator (ADVISOR), and how test results compare to the model predictions and published data. The chassis dynamometer testing included the FTP-75 emissions certification test procedure, highway fuel economy test, US06 aggressive driving cycle conducted at 0°C, 20°C, and 40°C, and the SC03 test performed at 35°C with the air conditioning on and with the air conditioning off. Data collection included bag and continuously sampled emissions (for the chassis tests), engine and vehicle operating parameters, battery cell temperatures and voltages, motor and auxiliary currents, and cabin temperatures.

This study compares emissions test results among seven compressed natural gas and seven standard gasoline 1996 Ford Crown Victoria taxi cabs. The study applies a mixed-effects analysis of covariance (ANCOVA) model on data from three rounds of high-mileage emissions tests performed at target odometer readings of 60,000, 90,000, and 120,000 miles (i.e., 96,540, 144,810, and 193,080 km). The ANCOVA model describes emissions deterioration within each vehicle sample, while also accounting for individual vehicle variability within the sample. The model was used to determine whether there are statistically significant differences between each fuel's emissions profiles and deterioration rates over the mileage range studied. Results are reported for non-methane hydrocarbons, carbon monoxide, oxides of nitrogen, carbon dioxide, formaldehyde, and fuel economy.

The first round of Federal Test Procedure (FTP) emissions testing of variable-fuel ethanol vehicles from the U.S. Federal fleet was recently completed. The vehicles tested include 21 variable-fuel E85 1992 and 1993 Chevrolet Lumina sedans and an equal number of standard gasoline Luminas. Results presented include a comparison of regulated exhaust and evaporative emissions and a discussion of the levels of air toxics, as well as the calculated ozone-forming potential of the measured emissions. Two private emissions laboratories tested vehicles taken from the general population of Federal fleet vehicles in the Washington, D.C., and Chicago metropolitan regions. Testing followed the standard U.S. Environmental Protection Agency's FTP and detailed fuel changeover procedures as developed in the Auto/Oil Air Quality Improvement Research Program.

The first round of emissions testing of flexible fuel methanol vehicles from the U.S. federal fleet was completed in 1995. The vehicles tested include 71 flexible fuel M85 1993 Dodge Spirits, 16 flexible fuel 1994 M85 Ford Econoline Vans, and a similar number of standard gasoline Dodge Spirits and E150 Ford Econoline Vans. Results presented include a comparison of regulated exhaust and evaporative emissions and a discussion of the levels of air toxins, and the ozone-forming potential (OFP) of the measured emissions. Three private emissions laboratories tested vehicles taken from the general population of federal fleet vehicles in the Washington D.C., New York City, Detroit, Chicago, and Denver metropolitan regions. Testing followed the standard U.S. Environmental Protection Agency's Federal Test Procedures (FTPs) and detailed fuel changeover procedures as developed in the Auto/Oil Air Quality Improvement Research Program.

The first round of emissions testing of light-duty alternative fuel vehicles placed in the U. S. federal fleet under the provisions of the Alternative Motor Fuels Act was recently completed. This undertaking included 75 Dodge B250 vans, of which 37 were dedicated compressed natural gas models, and 38 were standard gasoline controls. Data were collected on regulated exhaust emissions using the federal test procedures, and on a number of other quantities, through a statistically controlled program of investigation. Fuel economy results were also recorded. All test vehicles were operated in routine federal service activities under normal working conditions, adhering as closely as possible to Chrysler's prescribed maintenance schedules. The data analysis conducted thus far indicates that the compressed natural gas vehicles exhibit notably lower regulated exhaust emissions, on average, than their gasoline counterparts, and that these values are well within U.S.

The National Renewable Energy Laboratory (NREL) is managing a series of light duty vehicle chassis dynamometer emissions tests on alternative fuel vehicles for the U.S. Department of Energy (DOE). This testing program is part of a larger demonstration of alternative fuel vehicles that was mandated by the Alternative Motor Fuels Act of 1988 (AMFA). As part of the AMFA program, light duty vehicle performance, operational costs, maintenance, and fuel economy are also being collected by NREL's Alternative Fuels Utilization Program staff and disseminated through the Alternative Fuels Data Center (AFDC). In Phase 1 of the AMFA emissions test program (AMFA I), 18 vehicles were tested by three laboratories. All the vehicles tested under AMFA I were 1991 model year. In Phase 2 of the program (AMFA II), the number of vehicles was increased to nearly 300, including M85 Dodge Spirits, E85 (85% ethanol, 15% gasoline) Chevrolet Luminas, and compressed natural gas (CNG) Dodge passenger vans.