Exhibit 23 Consent of Independent Auditors We consent to the incorporation by reference in the Registration Statement (Form S-8 No. 333-79399 and No. 333- 9020) pertaining to The BP America Savings and Investment Plan of BP Amoco p.l.c. of our report dated June 18, 1999, with respect to the financial statements of The BP America Savings and Investment Plan included in this Annual Report (Form 11-K) for the year ended December 31, 1998. ERNST & YOUNG LLP Cleveland, Ohio June 18, 1999 24