Fatigue4Light project aims to investigate lightweight solutions adapted to the chassis part of EV to reach a 24-30% weight reduction. This will give a 12-15% weight saving from structural vehicle weight, and also increase EV safety due to reduced sprung mass. Solutions will be based on the introduction of especially developed material solutions with high fatigue performance (AHSS, stainless steel, Al alloys and hybrid metal-FRP materials), the development of new computer modelling with high fatigue prediction accuracy and new experimental methodologies that reduce the testing time. Sustainability of the proposed solutions will be continuously considered along project through an eco-design general approach. Environmental assessments through LCA, affordability based in LCC as well as social inclusion thanks to the recovery of CRMs from alternative waste streams will allow endowing Fatigue4Light into a novelty circular dimension. Attention will be given to manufacturing processes (cutting and welding) to improve the knowledge on their effect to the overall fatigue performance of chassis components. Six lab scale and industrial demonstrators will be defined to validate the proposed solutions. The fatigue model will be verified on demonstrators and then used in a virtual testing process to assess the weight reduction potential of the proposed materials, together with a redesign process oriented to lightweight the components while ensuring structural integrity. The project will reduce lead times to market due to the developed model and advanced fatigue testing methodologies and standardization will be followed. The final outcome is to give modelling and experimental tools for the lightweighting process on chassis parts subjected to fatigue. Clear and practical guidelines will be established with respect to different factors: eco design with proposed materials, advanced modelling approaches and the influence of forming processes on part performance.