Select the fluid from the drop-down list. If the fluid you required is not listed, or if the values provided are not correct, then add your own values for viscosity at 40C and 100C.
All hydraulic components, particularly the pumps and motors, are designed to work most efficiently within a limited specific range of fluid viscosity. This is what we called the optimum working range.
Hydraulic pump datasheets should also quote their maximum and minimum limits of operations. Pumps and motors are only permitted to run at these levels for limited periods of time. This may be during cold start or for intermittent hot running. Every system will be different but in general the longer a unit runs outside of its optimum working range, the quicker it will fail.