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Based on nationwide gasoline diary records of 5,000 families, an analysis was conducted of automobile misfueling (use of leaded gasoline in a vehicle designed for unleaded gasoline) trends in 1981 and 1982. The gasoline diary data base and the data handling and analysis techniques are described. Overall trends in vehicle misfueling are given, focusing on 1982 data, followed by more detailed information on the location and frequency of misfueling. Conclusions are presented indicating that while variations exist in misfueling by region and vehicle age, overall misfueling is a widespread problem, because catalyst-equipped cars are increasing in number and age.

This paper is the latest in a series of reports on the U.S. Department of Energy’s (DOE) comparison of Environmental Protection Agency (EPA) fuel economy estimates and on-road fuel economy performance. Earlier reports described a variety of analysis techniques, described DOE’s expanding inuse fuel economy data base, and presented analysis of trends in EPA- versus on-road fuel economy. The focus of this paper is the most recent additions to the data base (including data on light trucks and 1981 model-year cars), the development of DOE analysis techniques, and some of the more interesting trends revealed in this year’s analysis. Particular attention is given to model-year and vehicle-type differences, including driveline technology and model-type trends. The application of these results to improving fuel economy information programs and advertising for consumers is examined.

Abstract As part of a cooperative project with the Environmental Protection Agency the Department of Energy has conducted an analysis of consumer response to fuel economy information. The study examined consumer needs and level of understanding, alternative formats, fuel economy information in advertising and alternatives to the current Mileage Guide and Fuel Economy Label. The study techniques included a review advertising in the media, interviews with auto manufacturers' advertising departments, consumer surveys and focus group discussions with consumers and auto dealers. This paper presents the major quantitative and qualitative results with emphasis on (1) how the current Federal Fuel Economy Information Program fits into the overall fuel economy picture and (2) what kind of changes to the program could improve its effectiveness or reduce its cost.

Data were collected on alternative estimates of factors influencing fuel demand. These factors include: new vehicle registrations, vehicle miles of travel, vehicle scrappage and fuel economy. A methodology was then applied to assess the sensitivity of fuel demand to variations of each individual factor (within the range of the available data sources). A Base Case projection of fuel demand by vehicle type and fuel type is presented in detail. In addition, the impacts of two realistic alternative cases representing increased conservation efforts and increased fuel consumption are also analyzed.

The cost effectiveness of the current automobile fuel economy standards program is evaluated. A life cycle cost analysis is used to quantify the costs and benefits of fuel economy improvements stimulated by the program. The magnitude of these improvements is estimated by measuring the difference between the standards and a baseline “no standards” case. Due to the uncertainty associated with technology cost estimates, two scenarios are developed to bound the cost of fuel economy improvement; an “optimistic” scenario using technology cost and MPG gains documented by DOT and another “pessimistic” scenario based on conservative technology cost and fuel economy estimates. A review of fuel economy legislation concludes that marginal cost effectiveness to the nation be a significant criterion for setting future fuel economy standards.

The DOE inuse fuel economy data base was enlarged through the addition of data for 1978 as well as previous model years. A covariance analysis was used to identify variability among individual data sources. The analysis indicated that the variation among sources was small relative to the variation within individual sources and the sources pooled by model year. A unweighted linear regression in gallons per mile space was determined to be appropriate for evaluating the impact of the EPA to onroad relation on attainment of fuel economy standards and projection of fuel demand. The resulting model year relations did not significantly differ over the 15 to 25 mpg range. The data for the five model years were pooled, and a common regression was calculated. The regression relations, both model year and pooled model years, were analyzed for trends in shortfall as a function of mpg and time.

In response to growing concern over the validity of the EPA fuel economy numbers, the Department of Energy undertook a study of actual on-road fuel economy as it compares to the EPA numbers. This report covers the development of the data base for that study, the analysis techniques used for the initial phases of the work, and the preliminary results of that analysis. Data on over 5000 in-use vehicles were collected for model years 1974-1977. Data were obtained from a number of private and government groups for vehicles in fleet and typical consumer use, from on-road tests, and from in-use dynamometer tests. Comparisons using linear regressions were made between these mpg values and the EPA certification results for the same models. The results describe these differences as a function of vehicle mpg and model year. Other more specific comparisons are also made. An analysis of in-use fuel economy ranking, compared to the ranking by the EPA mpg numbers, is presented.

In November 1976, the Environmental Protection Agency promulgated rules covering the classification of automobiles for the purpose of fuel economy labeling and the Gas Mileage Guide. Since that time a number of changes have been made in the classification system and the interior volume measurements on which that system is based. This paper reports on the reasons for those changes and their impact on the classification of model year 1978 vehicles. The paper also discusses various trends in vehicle design as measured by interior and exterior volume, weight and fuel economy. Trends in varous design efficiency factors are examined for model years 1976-1978 and a data base is presented for future analysis.

The Federal Energy Administration analyzed possible approaches to classifying passenger automobiles to fulfill the requirements of Section 506 of the Energy Policy and Conservation Act for the labeling of 1977 and later model year cars with fuel economy information for the individual car and other “comparable cars” in its class. Weight, wheelbase, price, fuel economy, performance, exterior size, interior passenger space, and cargo (trunk) volume were examined as possible parameters for establishing car classes. To facilitate data handling, computer programs were developed to rank the representative sample of approximately 150 domestic and foreign vehicles of the 1976 new car fleet and sort them into classes.