Sloshing phenomena could seriously damage tank structures and reduce its lifetime. On the one hand, studies directly recommend the use of baffles to solve these problems, nevertheless on the other hand the existence of small tanks or plastic tanks without baffles confuse and complicate the case. The first aim in this thesis is to clarify the necessity of baffles for a particular diesel tank L120 H-Generation in Volvo front loaders. Then, the second aim is to improve the existing design. Four configurations are proposed and checked independently. Experiments in the lab, FEM static stresses analyses and vibrational simulations are done in order to fulfill the requirements. The conclusion of this thesis is that the dissipation of energy is highly recommended, so having an oblique baffle with holes could be a good way to reduce the sloshing and extend the lifetime of the tank.