The American Automobile Manufacturers Association retained MathPro Inc. to analyze economic implications for the U.S. refining sector of controlling the Distillation Index (DI) of all U.S. gasoline to a per-gallon cap of 1200 ("DI 1200"). The analysis focused on the Summer season. The analysis had four parts.

• Characterize the distribution of DI in the current U.S. gasoline pool and identify DI "hot-spots" - those segments of U.S. gasoline production that currently do not meet the contemplated DI 1200 standard;
• Characterize the typical intra-refinery distribution of DI in individual gasoline batches, using survey data made available by API;
• On the basis of their crude oil slates and process capacity profiles, identify refineries that likely produce, on average, high DI gasoline; and
• For these refineries, estimate - using ARMS - the average costs of complying with DI 1200.

The cost estimates developed in this study apply at the refinery gate. They did not include estimates of downstream costs that might be incurred to preserve DI quality achieved at the refinery or costs of complying with a possible regulatory program for DI.