In connection with the Annual Report of Frontier Oil Corporation (the “Company”) on Form 10-K/A for the period ending December 31, 2003 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Julie H. Edwards, Executive Vice President - Finance & Administration, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, to my knowledge, that:
| (1) The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and | |
| (2) The information contained in the Report fairly presents, in all material respects, the financial condition and result of operations of the Company. |
/s/ Julie H. Edwards
Julie H. Edwards
Executive Vice President - Finance & Administration,
Chief Financial Officer
October 13, 2004
