EXHIBIT 12.3 PACCAR Inc COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES PURSUANT TO SEC REPORTING REQUIREMENTS (Thousands of Dollars) Nine Months Ended September 30 1998 1997 -------- -------- FIXED CHARGES Interest expense PACCAR Inc and Subsidiaries (1) $121,705 $108,695 Portion of rentals deemed interest 10,915 4,579 -------- -------- TOTAL FIXED CHARGES $132,620 $113,274 -------- -------- -------- -------- EARNINGS Income before taxes - PACCAR Inc and Subsidiaries $473,135 $327,524 Fixed charges 132,620 113,274 -------- -------- EARNINGS AS DEFINED $605,755 $440,798 -------- -------- -------- -------- RATIO OF EARNINGS TO FIXED CHARGES 4.57x 3.89x (1) Exclusive of interest, if any, paid to PACCAR Inc. -15-