This article describes a numerical methodology, based on Finite Element approach, able to simulate, with a unique solution, the dynamic and structural response of a full vehicle running on fatigue reference roads. The current durability process is a multidisciplinary one based on a combination of three different phases: load definition, stress definition, and fatigue life prediction. For Long-Time Histories events, the second phase of this process is necessarily based on a Linear assumption using a Static or Dynamic approach. However, in durability events, some situations can lead the material to work in the plastic range, thus putting on the top the strength aspect of the performances and making these phases not independent and sequential, but strongly interdependent. The goal of the methodology reported in this article is to merge, in a unique numerical simulation, the load and stress definition phases. To this purpose, the solution of a full vehicle model of a commercial van, with a complete Finite Element representation of the body structure, running on fatigue roads, is investigated. This work represents an evolution of current load generation methodology and is able to quantify the impact of Nonlinear effects, such as contact and material plastic behavior, on structural response. A comparison of loads and stresses evaluated with the old approach and the new one is performed.