A team of stakeholders from ASTM Subcommittee D02.A on Gasoline and Oxygenated Fuels developed a revision to the seasonal and geographic volatility schedule for gasoline in the United States. The members of the team represented all classifications of the subcommittee: fossil and renewable fuels, automobile manufacturers, government regulators, logistics (shipping), and transport sectors. The team worked for two years with more than 1,300 hours of personal effort to revise this important schedule (see ASTM D4814, Standard Specification for Automotive Spark-Ignition Engine Fuel, Table 4). A volatility table has been included in ASTM D4814, and its predecessor ASTM D439-85a, Standard Specification for Automotive Gasoline (Withdrawn 1990), since the inception of these standard specifications. The original table was developed using weather data and decades of vehicle testing programs. This stakeholder group reviewed all of the historical and present data to develop volatility limits to provide a standard that should deliver acceptable driveability to the consumer.

The proposed revisions are based on agreed methodology for changes originating from weather data shifts over 20-year averaged hot and cold extreme temperatures for areas in the United States. These average temperatures were developed by a project sponsored and published by the Coordinating Research Council and then were used and supplemented with additional weather data when needed. Because there is no record of the process and procedures used to develop the original table based on 1950–1969 weather data, the task force recreated the original table using the original data with good fidelity. This provided an assurance that the procedures were in alignment with the original table development.

ASTM D4814, Table 4, includes volatility entries for every state in the United States for every month (two entries for the first and second halves of September). This results in 650 volatility limits to review and update if determined that a revision is needed. The volatility task force carefully reviewed each of these limits using agreed protocols and determined by consensus that 155 (about 24%) should be changed. Most of the changes reflect a decrease in volatility from the original table reflecting a conservative approach. The proposed changes were then reviewed by various stakeholders (e.g., fuel producers, pipelines, automakers, regulators) for feasibility and reasonableness. The proposed changes were balloted by Subcommittee D02.A and were accepted by consensus voting of the subcommittee and main committee in December 2023. These changes made to ASTM D4814, Table 4, are reflected in ASTM D4814-24 for spark ignition engine fuel.

ASTM D4814, Table 4, focuses on the United States, but the task force specifically improved the information in Section 5 and the Table 4 notes to make the information more internationally applicable.

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