EXHIBIT 23.1

                       CONSENT OF INDEPENDENT ACCOUNTANTS

As independent  public  accountants,  we hereby consent to the  incorporation by
reference in this  Registration  Statement of our report dated February 29, 2000
included in Ultramar Diamond Shamrock Corporation's Form 10-K for the year ended
December  31,  1999  and  to  all  references  to  our  Firm  included  in  this
Registration Statement.

                                  /s/ ARTHUR ANDERSEN LLP


San Antonio, Texas
October 2, 2000