§325.7 Allowable noise levels.

Motor vehicle noise emissions, when measured according to the rules of this part, shall not exceed the values specified in Table 1.

Table 1.—Maximum permissible sound level readings (decibel (A)) ^1,2
If the distance between the microphone location point and the microphone target point is—		Highway operations test				Stationary tests
		Soft site		Hard site		Soft site	Hard site
		35 mi/h or less	Above 35 mi/h	35 mi/h or less	Above 35mi/h	Soft site	Hard site
¹The speeds shown refer to measurements taken at sites having speed limits as indicated. These speed limits do not necessarily have to be posted.
²This table is based on motor carrier noise emission requirements specified in 40 CFR 202.20 and 40 CFR 202.21.
31 ft (9.5 m) or more but less than	35 ft (10.7 m)	87	91	89	93	89	91
35 ft (10.7 m) or more but less than	39 ft (11.9 m)	86	90	88	92	88	90
39 ft (11.9 m) or more but less than	43 ft (13.1 m)	85	89	87	91	87	89
43 ft (13.1 m) or more but less than	48 ft (14.6 m)	84	88	86	90	86	88
48 ft (14.6 m) or more but less than	58 ft (17.1 m)	83	87	85	89	85	87
58 ft (17.1 m) or more but less than	70 ft (21.3 m)	82	86	84	88	84	86
70 ft (21.3 m) or more but less than	83 ft (25.3 m)	81	85	83	87	83	85

[40 FR 42437, Sept. 12, 1975, as amended at 54 FR 50385, Dec. 6, 1989]

['CMV Parts and Maintenance']

['Vehicle maintenance']

...