Inertia classes in worldwide harmonized light vehicle test procedure (WLTP) development

Published: 2011.05.18

The definition of vehicle weight used for testing procedures is an important decision when drafting the regulation on determining emission values under the WLTP. Currently, different inertia class systems are used in the U.S., EU and Japan. A comparison of the current systems was compiled in WLTP-DTP-LabProcICE-011. The issue was discussed at the WLTP-DTP meeting on 12 January 2011 but no final decision was taken. The intention of this document is to provide a summary of the historical background, the current situation (with focus on the U.S. and EU), and different options discussed for the future; together with a proposal for moving forward based on the compiled facts. It is our hope that this fact sheet will assist the group in having a well-informed discussion in the next WLTP-DTP and WLTP meetings.

This working paper was submitted to the UNECE GRPE informal subgroup on the development of a worldwide harmonized light vehicles test procedure (WLTP-DTP) on the issue of inertia classes to be used in the development of the WLTP.