EXHIBIT 32.2

certification pursuant to
18 u.s.c. section 1350,
as adopted pursuant to
section 906 of the sarbanes-oxley act of 2002

In connection with this annual report of Rush Enterprises, Inc. (the “Company”) on Form 10-K for the year ended December 31, 2020 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Steven L. Keller, Chief Financial Officer and Treasurer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

1.     The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2.     The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

By:	/S/ STEVEN L. KELLER
Name:	Steven L. Keller
Title:	Chief Financial Officer and
	Treasurer
Date:	February 24, 2021