Add working fluids.
Periodic inspection, replenishment of the condition and replacement of working fluids are the basis for the correct operation of the car.
Oil in the engine, gearbox, coolant and power steering fluid, brake fluid or even fluid in the reservoir 
The sprinkler must comply with the specified requirements of the manufacturer. They can refer not only to properties and parameters, but also to the timing of their use. Problems arise when it is necessary to make up for the loss of fluid as a result of natural wear and tear or various repairs. The best solution is to replace all the fluid with a new one, as recommended by the manufacturer. However, this is not done, mainly because of the increase in the cost of such an operation. Refueling is much cheaper.
In the case of engine oil, if the manufacturer has only requirements for viscosity and quality, the level in the bowl can be temporarily topped up with oil that meets them, due to the lack of the original. Water, usually distilled, is usually sufficient for a small addition to the cooling system. If you need to add more liquid, it is best that it be exactly the same. True, there are liquids on the market that can be mixed with others, but before that, you should make sure that this is possible in your car. The same applies to brake fluid. Theoretically, if there is a DOT 4 liquid in the system, it can be supplemented with another one that also meets this standard. Unfortunately, these liquids can vary, so you need to know exactly if they can be mixed and, if so, which ones. This way we will avoid serious troubles.
Theoretically, the least of all problems should be with washer fluid. True, in summer there may even be water in the tank, but in winter you need to make sure that the contents of the tank have a sufficiently low freezing point. If the tank contains a mixture of summer and winter liquid with an unknown pour point, it is worth replacing it as soon as possible with a completely frost-resistant preparation.
