| GTR No. 15 WLTP | Worldwide Harmonized Light Vehicle Emissions Test Procedure | Worldwide Harmonized Light Vehicles Test Procedure <p>This GTR prescribes a test cycle and test procedures to measure the emissions (including off-cycle) and fuel efficiency of light-duty vehicles. The GTR was adopted at the March 2014 session of the World Forum.</p> <p>A supplemental "phase 1b" is underway to refine certain elements of the initial regulation. WP.29/AC.3 expects to consider a proposal for Amend. 1 to UN GTR No. 15 in November 2016 as result of Phase 1b activities.</p> <p>A second phase is expected to address low ambient temperature, high altitude test procedures, and possibly durability and conformity issues.</p> <p>A third phase would eventually include the addition of reference fuels, correlation across existing regional/national cycles, and introduction of emissions limits.</p> <p>The <a href="https://wiki.unece.org/display/trans/Latest+GTR+15" target="_blank">latest draft version</a> of the amended GTR is regularly updated by the WLTP informal working group.</p> <p>The regulation is also supplemented by a <a href="https://wiki.unece.org/display/trans/Gearshift+calculation+tool" target="_blank">gearshift calculation tool</a>. WLTP Worldwide Harmonized Light Vehicle Emissions Test Procedure GTR No. 15 GTR No. 15 | GTR | 15 |