Proposal to introduce provisions for non-original replacement silencing systems (NORESS, independent aftermarket muffler systems) with multiple, manually or electronically adjustable, rider-selectable operating modes or variable geometries (NORESS with “flexibilities”). These "flexibilities enable the replacement systems to meet the requirements of Annex 3 (i.e., during testing) while producing much higher noise (sound pressure) outside the Annex 3 conditions. This amendment would require such NORESS to meet the ASEP requirements of UN R9 and UN R41. The amendment further introduces language taken from UN R51. In effect, NORESS with flexibilities performance under normal driving conditions would not be permitted to deviate from its performance under testing.

Presentation in support of Germany’s proposal for amendments to UN R92 on non-original replacement exhaust silencing systems.