Engine oil. Do not panic

Often you can hear from customers that if you mix oils from different manufacturers, but with the same viscosity, then everything will collapse or fade. The conviction is so complete that I decided to clarify this situation a little.
To begin with, remember that all the oils are now made from at least two or more groups of base oils. Accordingly, already in the oil contain different components and according to the logic already when pouring into the engine of any oil, everything should fade and curdle. But for some reason this does not happen, although in oil there may be a base and a mineral water of the first - the second group in the mixture. Let's try to understand why and how everything happens.
All oil producers definitely do not recommend the use of another brand or other viscosity for refilling the oil. But it is connected more with insurance of own reputation. The reputation of the manufacturer is accumulated long enough, and several negative reviews may undermine it. Accordingly, if the buyer of oil drank somewhere on the track, some kind of oil and that something negative happens, then most likely he will not sin on the refilled oil for refilling, but for the main one, which was changed in the engine. Accordingly, if such a probability is present, it is simpler for the oil producer to prohibit adding oil, than to have at least a small, but potentially dangerous reputation for reputation. That is, the manufacturer of oil all the same it is easier to focus on their products, than to disassemble and explain to the consumer why somehow it turned out, when mixing different oils. Well, well, you can pour, but at your own peril and risk.
The same goes for car manufacturers. They are also important reputation and the less likely the consequences of using different technical fluids, the less headache the management. At the same time, neither the manufacturer of lubricants, but we consider only high-quality manufacturers, nor the automakers can unequivocally say why they do not recommend mixing different oils and everything is limited by vague formulations in the form of the danger of reducing the quality of the lubricant and the possible negative effects on the engine. But what exactly to decrease and how to express it negatively is given to the consumer to dream up.
As mentioned above, modern oils are a complex mix of different groups of base oils, polymer thickener and additive complexes. But we must still clearly understand that absolutely any liquid, whether engine oil or ATP is a set of technical characteristics that fit into the "plug" of the parameters for certain tolerances. That is, if somewhat simpler, engine oils of the same tolerances have exactly the same technical parameters within their "plugs" from the value of A to the value of B. Accordingly, the oils of the same tolerances should be as similar as possible. This does not mean that they are made from absolutely identical base oils, but according to technical parameters when properly manufactured, they will fit into an identical framework and a set of standardized values.
Let's go even further and take a little look at the historical perspective. During the formation of the European Union, the countries involved in it faced the issue of a uniform standardization of products produced in different territories. A huge amount of work has been done, a huge number of agreements have been literally in all spheres of human life and, as a result, the EU has created a uniform standard for all the participating countries. Standards and sphere of technical liquids and automobile oils have not bypassed standards. Suffice it to say that there are several hundred oil brands in Europe and many of them are local, that is, they are produced only on the territory of their countries. In order to solve the problem and not allow precedents, when a simple motorist can not find his own oil in a different region or country for refilling, the EU bureaucratic machine has gone the simplest way. Certification authorities were given the task to develop a test for the miscibility of oils, to prevent any negative consequences for the engine. This test now passes all types of oils that are allowed and can be sold in the European Union. In simple terms, to date, any European oil that has received official ACEA approval can be mixed with any other oil that also received such a tolerance in any proportions without harming the engine. There are certainly reasonable limitations in the form of identical tolerances on the ACEA or the tolerances of some automakers, but on the whole it is more like reinsurance. In any case, this approach is pleasantly pleasing and allows a simple motorist to feel more comfortable when traveling from the region or to different countries. But we must understand that to consider this situation with the mixing of oils, it is possible, as a matter of fact, fire, when there is no possibility to use the same kind of oil that is poured into your engine.
So, let's make a little conclusion. Oils can be mixed safely if necessary, observing identical viscosity characteristics