The future of mobility presents various challenges. For the future CO2 targets, savings in the existing fleet are necessary. In this paper and the accompanying poster, the project reFuels- Rethinking Fuels is introduced and results of the de-veloped gasoline and diesel fuels are presented. The aim of the project is to enable the use of fuels from renewable sources via BtL and PtL pathways as drop-in components to fossil fuels for use in the existing vehicle fleet. For this purpose, it is shown how the gasoline fuel blend G40 with regenerative fuel components produced from biomass has advantages in particle behavior in RDE tests com-pared to conventional fossil gasoline. In single-cylinder tests, a significantly re-duces proportion of aromatics larger than or equal to C9 in the optimized bioliq® fuel leads to improved particle emissions. Tests with diesel and components from regenerative sources (PtL and BtL), which mixture was within EN 590, show no adverse thermodynamic behavior but advantages from a raw emission point of view. On production engine at cold start conditions at -7 °C, paraffinic diesel shows improved particulate emissions under transient driving maneuvers, espe-cially in idling phases, compared to fossil diesel.