This paper deals with hydraulic cylinders with and without end position cushioning. The reduction of the velocity at the end of the stroke is important in order to preserve the structural integrity and to avoid undesirable motion of the load. The mathematical model of such a hydraulic cylinder is shown, as well as the Matlab functional diagram for the system. It is also revealed the role of the working fluid, considering the actual recommendations regarding the biodegradable substances. It was considered both mineral base liquids and vegetable base liquids. The functional diagram offers the possibility to view for the hydraulic system the variation of the speed, flow rate, rate and stroke of the piston, in both cases: with and without end position cushioning. Is also shown a CFD analysis of fluid flow through the supply/outlet connections of the hydraulic cylinder.