UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) September 2, 2025

PACCAR Inc

(Exact name of registrant as specified in its charter)

Delaware

001-14817

91-0351110

(State or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

777 106^th Avenue NE, Bellevue, WA 98004

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code (425) 468-7400

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2.):

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading
Symbol(s)

Name of each exchange

on which registered

Common stock, $1 par value

PCAR

The NASDAQ Stock Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 5.02

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

(b) On September 2, 2025, Darrin C. Siver, Executive Vice President, announced his retirement from PACCAR after 32 years of service. Mr. Siver’s retirement is effective January 5, 2026.

Item 8.01.

Other Events

John N. Rich, Senior Vice President and Chief Technology Officer, will maintain responsibilities for PACCAR’s global technology initiatives and will assume responsibilities for Peterbilt Motors Company effective January 5, 2026.

Laura J. Bloch, Senior Vice President, will maintain responsibilities for Kenworth Truck Company and PACCAR Parts and will assume responsibilities for Corporate Quality and Purchasing effective January 5, 2026.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

PACCAR Inc

Date: September 5, 2025

/s/ M. K. Walton

M. K. Walton

Vice President and General Counsel

PACCAR INC 8-K