Temperature Indicator does not reach 90

According to the previous owner of my vehicle, there were 70 sender, so the temperature indicator never comes when the vehicle should normally be 90 or a little below when it gets hot. Or could there be a problem with the thermostat?

There may be a problem with the thermostat. But I think there is another problem after the touch, the head hurts, as well as the advantage, as well as the disadvantage, fuel consumption increases a little. as the engine gets too late in winter. Its advantage does not overheat, it does not cost engine.