§FMCSR.com
Historical textIn force on June 1, 2010Source: annual CFR editions 2001–2016

§ 325.93 Tires.

Wording in the annual edition revised as of Oct. 1, 2001, superseded January 1, 2017.

govinfo, 2009 edition ↗
Before Jan. 1, 2017 the record is one snapshot per annual CFR edition, revised as of October 1. This is the 2009 edition's wording. An amendment that took effect between Oct. 1, 2009 and June 1, 2010 would not appear until the next edition, so check the citations below and the Federal Register for exact effective dates.
49 CFR § 325.93 — Tires.. Text in force on June 1, 2010. This wording effective October 1, 2001 to January 1, 2017. Source: govinfo, 2009 edition, https://www.govinfo.gov/app/details/CFR-2009-title49-vol5/CFR-2009-title49-vol5-sec325-93. Retrieved from FMCSR.com, https://fmcsr.com/reg/325.93?asof=2010-06-01, on October 26, 2026. Unofficial compilation; verify against the official source.

(a) Except as provided in paragraph (b) of this section, a motor vehicle does not conform to the visual tire inspection requirements, 40 CFR 202.23, of the Interstate Motor Carrier Noise Emissions Standards, if inspection of any tire on which the vehicle is operating discloses that the tire has a tread pattern composed primarily of cavities in the tread (excluding sipes and local chunking) which are not vented by grooves to the tire shoulder or circumferentially to each other around the tire.

(b) Paragraph (a) of this section does not apply to a motor vehicle operated on a tire having a tread pattern of the type specified in that paragraph, if the motor carrier who operates the motor vehicle demonstrates to the satisfaction of the Administrator or his/her designee that either—

(1) The tire did not have that type of tread pattern when it was originally manufactured or newly remanufactured; or

(2) The motor vehicle generates a maximum sound level reading of 90 dB(A) or less when measured at a standard test site for highway operations at a distance of 15.3 meters (50 feet) and under the following conditions:

(i) The measurement must be made at a time and place and under conditions specified by the Administrator or his/her designee.

(ii) The motor vehicle must be operated on the same tires that were installed on it when the inspection specified in paragraph (a) of this section occurred.

(iii) The motor vehicle must be operated on a highway having a posted speed limit of more than 56.3 kph (35 mph).

(iv) The sound level measurement must be made while the motor vehicle is operating at the posted speed limit.

[40 FR 42437, Sept. 12, 1975, as amended at 60 FR 38743, July 28, 1995]

Amendment history

3 distinct wordings on file since Oct. 1, 1996
  1. Jan. 1, 2017 → presenteCFR, day-precisediff vs. previous
    [40 FR 42437, Sept. 12, 1975, as amended at 60 FR 38743, July 28, 1995; 66 FR 49869, Oct. 1, 2001]
  2. Oct. 1, 2001 → Jan. 1, 2017annual editions 2001–2016diff vs. previousviewing
    [40 FR 42437, Sept. 12, 1975, as amended at 60 FR 38743, July 28, 1995]
  3. Oct. 1, 1996 → Oct. 1, 2001annual editions 1996–2000
    [40 FR 42437, Sept. 12, 1975, as amended at 60 FR 38743, July 28, 1995]

A new entry appears whenever the regulatory words change between government snapshots. Day-precise from the eCFR (2017 onward); before that, one snapshot per annual CFR edition (revised as of October 1). Bracketed citations are the Federal Register history printed with the section.