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Is there a "recommended" calculation tool for performing Complex Model calculations? Related question: In view of inconsistencies between the current regulations and the Complex Model spreadsheet posted by EPA, which should industry follow? If the answer is the regulation, can EPA confirm that the regulation is consistent with the actual Complex Model developed by EPA? Will EPA use the spreadsheet to determine if fuels are in compliance?

See More Frequent Questions about Fuels Registration, Reporting, and Compliance Help.

The version of the Complex Model that is legally binding is that contained in the Federal Register.9 The printed version of the Complex Model in the Federal Register does contain several minor errors which are under correction through a proposed rulemaking (62 FR 37337, July 11, 1997). With these minor corrections, the Complex Model contained in the Federal Register will be consistent with the spreadsheet version.

The Lotus spreadsheet which EPA made available through the internet is being used by both the Office of Mobile Sources and the Office of Enforcement and Compliance Assurance in verifying refiners' compliance with the performance standards. The Agency has no plans to use a version of the Complex Model other than this Lotus spreadsheet. Although a refiner choosing to use the spreadsheet version of the Complex Model bears responsibility for any errors it may contain, to date no errors have been found in the spreadsheet. (11/10/97)

9 See 59 Fed. Reg. 7716 (Feb. 16, 1994); 59 Fed. Reg 36944 (July 20, 1994); see also 40 CFR §80.45.

This question and answer was posted at  List of Reformulated Gasoline and Anti-Dumping Questions and Answers: July 1, 1994 through November 10, 1997 (pdf) (2.98 MB, July 2003)

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Last updated on June 3, 2025
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