Inertia Classes Proposal - ICCT（惯性类提案国际清洁）.pdf

International Council on Clean Transportation Working Paper #5 Inertia Classes Proposal WLTP-DTP-LabProcICE-077 Submission to the UNECE GRPE informal subgroup on the development of a worldwide harmonized light vehicles test procedure (WLTP-DTP) June 3, 2011 INTRODUCTION Historically the weight of a vehicle was represented by hanging rotating inertia mass on a dynamometer. This approach required the use of discrete inertia classes and an upper limit for inertia mass. Modern electronic dynamometers do not impose these limitations anymore. As a result it is now possible to revise existing test procedures and provide more accurate emission / fuel consumption values to consumers. This document builds on more detailed explanations that were given in the documents WLTP-DTP-LabProcICE-054 and WLTP-DTP-LabProcICE-067, and presents, for dis- cussion, a proposal for defining inertia classes for the WLTP GTR. GENERAL The definition of inertia classes is closely linked to the definition of vehicle reference mass and vehicle test groups. Inertia Classes Proposal WLTP-DTP-LabProcICE-007 REFERENCE MASS Reference mass (also called test weight basis, loaded vehicle weight or vehicle test mass) can vary for two vehicles with the same technical parameters but differences in the optional equipment. Whereas Japan and the US take into account optional equip- ment when determining the reference mass of a vehicle, this is currently not the case in Europe and India. Furthermore, there are differences in the definition of reference mass across these countries / regions that arise due to differences in including fuels, tools, etc. See Table 1