EXHIBIT 9.1 PETRO-CANADA INTEREST COVERAGE (ALL AMOUNTS IN MILLIONS OF DOLLARS, EXCEPT AS INDICATED) TWELVE MONTHS ENDED ---------------------------------------- MARCH 31, 2003 DECEMBER 31, 2002 ------------------ ------------------- ACTUAL ACTUAL ------------------ ------------------- Interest coverage on long-term debt: EARNINGS BASIS Net earnings 1,470 974 plus: provision for income taxes 1,282 854 interest expense 205 187 ------------------ ------------------- 2,957 2,015 ================== =================== Interest expense 205 187 plus: capitalized interest 4 4 ------------------ ------------------- 209 191 ================== =================== Interest coverage on earnings basis (times) 14.1 10.5 ================== =================== CASH FLOW BASIS Cash flow 2,980 2,276 plus: interest expense 205 187 current income taxes 1,285 959 ------------------ ------------------- 4,470 3,422 ================== =================== Interest expense 205 187 plus: capitalized interest 4 4 ------------------ ------------------- 209 191 ================== =================== Interest coverage on cash flow basis (times) 21.4 17.9 ================== ===================