Analytical data for 905 samples of motor gasoline, were collected from service stations throughout the country and were analyzed in the laboratories of various refiners, motor manufacturers, and chemical companies. The data were submitted to the Bartlesville Energy Technology Center for study, necessary calculations, and compilation under a cooperative agreement between the Bartlesville Energy Technology Center (BETC) and the American Petroleum Institute (API). The samples represent the products of 30 companies, large and small, which manufacture and supply gasoline. These data are tabulated by groups according to brands (unlabeled) and grades for 17 marketing districts into which the country is divided. A map included in this report, shows marketing areas, districts and sampling locations. The report also includes charts indicating the trends of selected properties of motor fuels since winter 1959-60survey for the leaded gasolines, and since winter 1979-80 survey for the unleaded gasolines. Sixteen octane distribution percent charts for areas 1, 2, 3, and 4 for unleaded antiknock index (R+M)/2 below 90.0, unleaded antiknock index (R+M)/2 90.0 and above, leaded antiknock index (R+M)/2 below 93.0, and leaded antiknock index (R+M)/2 93.0 and above grades of gasoline are presented in this report. The antiknock (octane) index (R+M)/2 averages of gasoline sold in thi~ country were 87.4 for unleaded below 90.0, 91.7 for unleaded 90.0 and above, and 88.9 for leaded below 93.0. Only one sample was reported as 93.0 for leaded gasolines with an antiknock index (R+M)/2 93.0 and above. , Statistical Assistant. •INTRODUCTION The properties of motor fuels sold through service stations in the United States are reported in accordance with a cooperative agreement between the American Petroleum Institute and the Bartlesville Energy Technology Center of the United States Department of Energy. By agreement with the American Petroleum Institute, identification of the source of data is confidential. This report presents analytical data for 905 samples that represent the products of 30 companies. Company representatives collected and analyzed the samples during December 1981, and January and February 1982. As in previous surveys, the gasoline data in this survey include those from both large and small suppliers. Laboratories of various refiners, motor manufacturers, and chemical companies obtained and submitted the data to the Bartlesville Energy Technology Center for study, calculations, and compilation. Motor-gasoline survey reports published since 1971 are listed on page 7. • Analytical data required for a complete gasoline analysis were not available for many of the samples. Tests in this category, the number of samples available and used in this report, and the percent of the total samples represented for that test include the following: Number of Percent of Test samQies used total samQies Gravity 861 95.
