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                                                        EXHIBIT 23.1


                        CONSENT OF INDEPENDENT AUDITORS


We consent to the incorporation by reference in the following Registration
Statements (i) Form S-8 (No. 33-52148) pertaining to the Ultramar Diamond
Shamrock Corporation 1992 Long-Term Incentive Plan, (ii) Form S-8 (No.
33-62894) pertaining to the Ultramar Diamond Shamrock Corporation Restricted
Share Plan for Directors, (iii) Form S-8 (No. 333-19131) pertaining to the
Diamond Shamrock Inc. 1987 Long-Term Incentive Plan and the Diamond Shamrock
Inc. Long-Term Incentive Plan, (iv) Form S-3 (No. 33-74162) pertaining to the
Ultramar Diamond Shamrock Corporation Stock Purchase and Dividend Reinvestment
Plan, and (v) Form S-3 (No. 33-82662) pertaining to the registration of
$200,000,000 of debt securities of our report dated February 7, 1997 with 
respect to the consolidated financial statements and schedule of Ultramar
Diamond Shamrock Corporation (formerly Ultramar Corporation) included in this
Annual Report (Form 10-K) for the year ended December 31, 1996.


                                                        /s/ ERNST & YOUNG LLP

San Antonio, Texas
March 25, 1997