Exhibit 23.1 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Statement No. 333-25379 and No. 333-39070 of Tesoro Petroleum Corporation on Form S-8 and in Registration Statement No. 333-51789 and No. 333-84018 of Tesoro Petroleum Corporation on Form S-3 of our report dated February 14, 2003, appearing in this Annual Report on Form 10-K of Tesoro Petroleum Corporation for the year ended December 31, 2002. /s/ DELOITTE & TOUCHE LLP San Antonio, Texas March 20, 2003