EXHIBIT 12.3 PACCAR AND SUBSIDIARIES COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES (Thousands of Dollars) Three Months Ended March 31 2000 1999 ------------------------------------- FIXED CHARGES Interest expense - PACCAR and subsidiaries (1) $ 55,395 $ 42,660 Portion of rentals deemed interest 4,965 4,437 ------------------------------------- TOTAL FIXED CHARGES $ 60,360 $ 47,097 ------------------------------------- EARNINGS Income before taxes - PACCAR and subsidiaries $ 242,752 $ 187,450 Fixed charges 60,360 47,097 ------------------------------------- EARNINGS AS DEFINED $ 303,112 $ 234,547 ------------------------------------- RATIO OF EARNINGS TO FIXED CHARGES 5.02x 4.98x (1) Exclusive of interest, if any, paid to PACCAR. -14-