Exhibit 23 CONSENT OF INDEPENDENT AUDITORS We consent to the incorporation by reference in this Annual Report (Form 10-K) of PACCAR Inc of our report dated February 18, 2000, included in the 1999 Annual Report to Shareholders of PACCAR Inc. We also consent to the incorporation by reference in the Registration Statement (Form S-8 No. 2-83673) pertaining to the 1981 Long-Term Incentive Plan and in the Registration Statement (Form S-8 No. 33-47763) pertaining to the 1991 Long-Term Incentive Plan of PACCAR Inc of our report dated February 18, 2000, with respect to the consolidated financial statements of PACCAR Inc incorporated by reference in the Annual Report (Form 10-K) for the year ended December 31, 1999. /s/ Ernst & Young LLP ERNST & YOUNG LLP Seattle, Washington March 17, 2000