Northern Territory Consolidated Regulations Northern Territory Consolidated Regulations(1) The outlet of the exhaust system fitted to a motor vehicle with a GVM over 4.5 tonnes (except a bus) must extend:
(a) behind the back seat; and
(b) at least 40 millimetres beyond the outermost joint of the floorpan that is not continuously welded or permanently sealed; and
(c) to the edge of the vehicle, if:
(i) the body of the vehicle is permanently enclosed; and
(ii) the vehicle is not fitted with a vertical exhaust system; and
(d) no further than the edge of the vehicle at its widest point.
(2) The outlet must discharge the main exhaust flow to the air:
(a) if the vehicle is fitted, or required under a law of this jurisdiction to be fitted, with an exhaust system with a vertical outlet pipe:
(i) at an angle above the horizontal; and
(ii) at least 150 millimetres above the cab of the vehicle; and
(iii) rearwards or to the right of the vehicle; and
(b) in any other case:
(i) horizontally or at
an angle of not over
45° downwards; and
(ii) under 750 millimetres above ground level; and
(iii) rearwards or to the right of the vehicle.
(3) An exposed section of a vertical exhaust system fitted to a motor vehicle (except a bus) with a GVM over 4.5 tonnes must be positioned or shielded to prevent injury.
(4) The outlet of the exhaust system fitted to a bus with a GVM over 4.5 tonnes must:
(a) be as near as practicable to the rear of the vehicle; and
(b) extend no further than the edge of the bus at its widest point.
(5) The outlet must discharge the main exhaust flow to the air:
(a) if the bus is fitted, or required under a law of this jurisdiction to be fitted, with an exhaust system with a vertical outlet pipe:
(i) behind the passenger compartment; and
(ii) at an angle above the horizontal; and
(iii) upwards or rearwards; and
(b) in any other case:
(i) horizontally or at
an angle of not over
45° downwards; and
(ii) rearwards or to the right of the vehicle.
(6) A vertical exhaust system fitted to a motor vehicle with a GVM over 4.5 tonnes must:
(a) if the vehicle is fitted with an exhaust system with a vertical outlet pipe that does not direct the main exhaust flow straight up – direct the flow rearwards at an angle within 0° to 45° of the longitudinal centre line of the vehicle; and
(b) if a rain cap is fitted to the outlet pipe – be installed so the hinge of the cap is at an angle of 90° (plus or minus 10°) to the longitudinal centre line of the vehicle when viewed from above.
Bus exhaust outlet pipe