Series of proposals from the WLTP informal group to improve and clarify the text of GTR 15 on light vehicle emissions. This document is also available with track changes: pdf version and doc version.

Proposal to align UN R115 with the GTR No. 15 WLTC test cycle.

Proposal to introduce improvements and amendments concerning the evaporative emission family definitions and the Type 4 test procedures with regard to test equipment requirements and calibrations, evaporative emission measurement enclosures, and use of variable volume SHED facilities. The document is also available in versions with track changes: pdf format and doc format.

Proposal to clarify the meaning and use of “peripheral devices”.

Proposal to align the provisions of the 03 series of amendments to UN R24 with UN R85. Other amendments are proposed in order to bring the format of UN R24 up to date.

Proposal to reduce testing burdens by introducing an alternative test method to “decrease the charge air cooler outlet temperature by the same amount that the ambient conditions for the vehicle test varied from the standard temperature.” This aligns with SAE J1349, “9.3 Application of Vehicle Transient Data to Net Power Test.”

Proposal to clarify the relationship between approval levels, reference fuels and PN limits for PI vehicles and to modify the calculation formulae for determination of evaporative emissions in accordance with changes already agreed in UN GTR No. 19.