Section 120(1) in The Central Motor Vehicles Rules, 1989
(1)[Every motor vehicle including agricultural tractor] [Substituted by GSR 111(E), dated 10.2.2004, for 'Every motor vehicle'(w.e.f. 10.8.2004).] [and combine harvester] [Inserted by Notification No. G.S.R. 212 (E) dated 20.3.2015 (w.e.f. 1.4.2015)] shall be fitted with a device(hereinafter referred to as a silencer) which by means of an expansion chamber or otherwise reduces as far as practicable, the noise that would otherwise be made by the escape of exhaust gases from the engine.
