EXHIBIT 12.3 PACCAR Inc COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES PURSUANT TO SEC REPORTING REQUIREMENTS (Thousands of Dollars) Three Months Ended March 31 1998 1997 ------------------------------------- FIXED CHARGES Interest expense PACCAR Inc and Subsidiaries (1) $ 38,459 $ 35,318 Portion of rentals deemed interest 1,791 1,526 ------------------------------------- TOTAL FIXED CHARGES $ 40,250 $ 36,844 ------------------------------------- ------------------------------------- EARNINGS Income before taxes - PACCAR Inc and Subsidiaries $ 157,132 $ 88,690 Fixed charges 40,250 36,844 ------------------------------------- EARNINGS AS DEFINED $ 197,382 $ 125,534 ------------------------------------- ------------------------------------- RATIO OF EARNINGS TO FIXED CHARGES 4.90x 3.41x (1) Exclusive of interest, if any, paid to PACCAR Inc. -13-