EXHIBIT 15.1 INDEPENDENT ACCOUNTANTS' AWARENESS LETTER Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 Ladies and Gentlemen: We are aware that Diamond Shamrock, Inc. has included our report dated May 10, 1996 (issued pursuant to the provisions of Statement on Auditing Standards No. 71) in the Prospectus constituting part of Amendment No. 1 to Registration Statement No. 333-4157 on Form S-3 and in Post-Effective Amendment No. 2 to Registration Statement No. 33-59451 on Form S-3 to be filed on or about June 11, 1996. We are also aware of our responsibilities under the Securities Act of 1933. Yours very truly, /s/ PRICE WATERHOUSE LLP PRICE WATERHOUSE LLP San Antonio, Texas June 11, 1996 W3992.TW