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Some Evidence on Determinants of Fuel Economy as a Function of Driving Cycle and Test Type
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Abstract
Statistical methods are used with 107 vehicles whose fuel economy was presented and reported for five test types in a single publication by Consumers Union (CU) for 1986-1988 vehicles. Standard loglinear statistical formulations (i.e., multiplicative models of interactions) are used with data from this and supplementary sources to develop coefficients estimating the percent fuel economy gain per percent change in engine/vehicle design characteristic. The coefficients are developed for the five different test conditions evaluated by CU and are compared with each other on the basis of attributes of the tests. The insights of engineering models are used to develop expectations regarding the shift in size of coefficients as driving cycles change. For the effects of weight reduction, a range of coefficients is estimated whose high and low values are remarkably consistent with the range of values developed by nine sources cited in the 1992 National Academy of Sciences (NAS) study, “Automotive Fuel Economy”. In both the engineering models and the statistical model, the effect of weight is estimated to be higher in urban driving than in highway driving. For two test categories - field tests and dynamometer tests - the benefits of weight reduction are statistically estimated to be greatest in urban driving conditions. The effect of weight in the statistical model is estimated to be greater than in the previously developed engineering models, when terms including weight are estimated to vary due to changes in weight. Prior engineering model equations do not write weight into the terms explaining fuel consumption during idle and unpowered deceleration (predominantly braking). The effect on idle fuel flow rate of designing vehicles to hold performance roughly constant by maintaining power per kilogram and/or displacement per kilogram is examined, and its implication for the size of the weight effect is simply approximated from Sovran’s 1983 engineering model results. The fuel-economy-decreasing effect of the desire for performance is estimated to be somewhat larger in the statistical analysis than in the NAS study, when engine technology is held constant.
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Citation
Santini, D. and Anderson, J., "Some Evidence on Determinants of Fuel Economy as a Function of Driving Cycle and Test Type," SAE Technical Paper 931804, 1993, https://doi.org/10.4271/931804.Also In
References
- National Research Council 1992 Automotive Fuel Economy: How Far Should We Go? National Academy Press Washington, DC
- Sovran, G. Bohn, M.S. 1981 Formulae for the Tractive Energy Requirements of Vehicles Driving the EPA Schedules SAE Paper 810184 SAE International Warrendale, PA
- Sovran, G. 1983 Tractive-Energy-Based Formulae for the Impact of Aerodynamics on Fuel Economy Over the EPA Driving Schedules SAE Paper 830304 SAE International Warrendale, PA
- An, F. 1992 Automobile Fuel Economy and Traffic Congestion PhD. Dissertation Department of Applied Physics, University of Michigan Ann Arbor, MI
- An, F. Ross, M. 1993 A Model of Fuel Economy and Driving Patterns SAE Paper 930328 SAE International Warrendale, PA
- Hanks, J.W. Lomax, T.J. 1989 Roadway Congestion in Major Urban Areas Federal Highway Report FHWWX-90-1131-2 Texas Transportation Institute College Station, TX
- Chelimsky, E. 1991 Traffic Congestion: The Need and Opportunity for Federal Involvement U.S. General Accounting Office Testimony GAO/T’-PEMD-91-10 Washington, DC May 29
- Cameron, M. 1991 Transportation Efficiency: Tackling Southern California’s Air Pollution and Congestion Regional Institute of Southern California Berkeley, CA
- Watterson, W. 1991 Linked Simulation of Land Use and Transportation Systems Conference on Transportation and Global Climate Change: Long- Run Options U.S. Environmental Protection Agency, U.S. Department of Energy, and U.S. Department of Transportation Pacific Grove, Calif. Aug. 25-28
- White, R.E., et al., 1991 Smart Highways U.S. General Accounting Office Report GAOlPEMD-91-18 Washington, DC
- Wang, Q. Santini, D. 1993 Magnitude and Value of Electric Vehicle Emissions Reductions for Six Driving Cycles in Four U.S. Cities with Varying Air Quality Problems Paper 930526 presented at the 72nd Annual Meeting of the Transportation Research Board Washington, DC Jan. 10-14
- Wicks 1991 Development of a Model to Predict Electric Vehicle Performance over a Variety of Driving Conditions” and “Potential Benefits from Applying Electric Vehicle Technology to Engine Driven Vehicles Proceedings of the 27th Intersociety Energy Conversion Engineering Conference San Diego, CA Aug. 5
- Fwa, T. Ang, B. 1992 Estimating Automobile Fuel Consumption in Urban Traffic Transportation Research Record 1366 Transportation Research Board, National Research Council Washington, DC
- Murrell, D. 1980 Passenger Car Fuel Economy: EPA and Road EPA Report EPAJ3-80-010 Ann Arbor, MI
- MacCready, P. 1991 Electric and Hybrid Vehicles Conference on Transportation and Global Climate Change: Long-Run Options U.S. Environmental Protection Agency, U.S. Department of Energy, and U.S. Department of Transportation Pacific Grove, CA Aug. 25-28
- Heavenrich, R.M. Murrell, J.D. Hellman, K.D. 1991 Light Duty Automotive Technology and Fuel Economy Trends Through 1991 U.S. EPA Report EPAlAAlCTABl91-02 Office of Mobile Sources Ann Arbor, MI
- Young, Y.R. 1991 Regression Analysis for Performance of Light Duty Vehicles, National Highway Traffic Safety Administration Report DOT HS 807 763 National Highway Traffic Safety Administration Washington, DC
- Markovich 1989 Used Car Buying Guide 1989 Consumers Union Mount Vernon, NY
- Consumers Union 1993 Consumer Reports: The Annual Auto Issue, Yonkers, NY
- Austin, T.G., 1992 An Analysis of Driving Patterns in Los Angeles During 1992 3rd Annual CRC-APRAC On-Road Vehicle Emissions Workshop Sacramento, CA Dec. 3
- Cleary, J. Levenbach, H. 1982 The Professional Forecaster Lifetime Learning Publications Belmont, CA
- Chilton Book Co. 1989 Chilton’s Auto Repair Manual 1983-1990 Radnor, PA
- Chilton Book Co. 1989 Chilton’s Import Car Repair Manual 1983-1990 Radnor, PA
- Automotive News 1986 1986 Market Data Book. No. 5125 Crain Publications Detroit, MI 37 50
- Automotive News 1987 1987 Market Data Book. No. 51 78 Crain Publications Detroit, MI 57 70
- Automotive News 1988 1988 Market Data Book. No. 5235 Crain Publications Detroit, MI 41 53
- Berger, J.O. Smith, M.H. Andrews, R.W. 1990 A System for Estimating Fuel Economy Potential due to Technology Improvements presented at the workshop of the Committee on Fuel Economy of Automobiles and Light Trucks Irvine, CA July 8-12 University of Michigan Ann Arbor, MI