1 QUAKER STATE CORPORATION AND SUBSIDIARIES EXHIBIT 12 Statement re Computation of Ratio of Earnings to Fixed Charges FOR THE NINE MONTHS ENDED SEPTEMBER 30 (in thousands) 1998 1997 ------- ------- Interest expense $21,899 $20,251 Interest factor of rental expense 6,883 6,879 ------- ------- Total fixed charges $28,782 $27,130 ======= ======= Income from continuing operations before income taxes $ 8,929 $28,970 Fixed charges 28,782 27,130 ------- ------- Total earnings $37,711 $56,100 ======= ======= Ratio of earnings to fixed charges 1.3 2.1 ======= ======= (1) Interest factor of rental expense computed based on: (a) average interest factor from a sample of leases for operations representing in excess of 50% of rentals from continuing operations, and (b) one-third factor of rentals for other operations. 20