This document summarizes the key findings of the Fugitive and Unburned Methane Emissions from Ships (FUMES) project, a collaboration between the International Council on Clean Transportation (ICCT), Explicit ApS, and the Netherlands Organization for Applied Scientific Research (TNO). The FUMES project resulted in the most comprehensive dataset of real-world methane emissions from LNG-fueled ships to date. The team conducted three measurement campaigns (plume, onboard, and fugitive) to assess real-world methane emissions associated with LNG-fuelled ships. Based on the results of the FUMES study, the co-sponsors propose that the Group accept at least 6% as the default TtW Cslip value for LPDF 4-stroke engines under the IMO’s LCA Guidelines.