EXHIBIT 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation by reference in this Form 8-K of Ultramar Diamond Shamrock Corporation and into the previously filed Registration Statements of Ultramar Diamond Shamrock Corporation on Form S-3 (Nos. 33-74162, 33-82662 and 333-28737) and on Form S-8 (Nos. 33-52148, 33-62894, 333-19131, 333-27697, 333-27703, 333-27699 and 333-27701) of our report dated January 21, 1997, included in the Annual Report on Form 10-K of Total Petroleum (North America) Ltd. for the year ended December 31, 1996. It should be noted that we have not audited any financial statements of Total Petroleum (North America) Ltd. subsequent to December 31, 1996, or performed any audit procedures subsequent to the date of our report. ARTHUR ANDERSEN LLP /s/ Arthur Andersen LLP Denver, Colorado October 3, 1997