Exhibit 99.2

                           CERTIFICATION PURSUANT TO
                            18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                 SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


I, William E. Hantke, Executive Vice President and Chief Financial Officer of
Premcor Inc., Premcor USA Inc. and The Premcor Refining Group Inc. (each a
"Company"), pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, do hereby
certify as follows with respect to each Company:

1.   The quarterly report on Form 10-Q of the Company for the period ended
     September 30, 2002, 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 such Form 10-Q fairly presents, in all
     material respects, the financial condition and results of operations of the
     Company.

     IN WITNESS WHEREOF, I have executed this Certification on this 7th day of
November, 2002.

                                       By: /s/ William E. Hantke
                                           -------------------------------------
                                           Executive Vice President and
                                           Chief Financial Officer