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Many novice car enthusiasts wonder whether you can mix oils of different manufacturers, categories, and viscosity grades for the engine of the car. What will be the consequences and how to avoid them. Let’s get to the bottom of it.

Oil from different manufacturers

Any oil consists of a base and a set of additives, which give individual qualities to the base oil. In the possible incompatibility of the bases of different manufacturers lies the first problem. Different manufacturers have different technologies and different methods of base production, which, as a result, may have different properties (especially in the case of synthetics). Because of the different bases, there may be problems when mixing the same synthetic oils, but from different manufacturers. This is because a more serious factor comes into play: additives!

In order to achieve the same viscosity and temperature values, manufacturers solve different problems with certain properties of their own base bases. A set of additives, which finally solves their problem of bringing them to the standard, can turn out to be radically different.

When these two different sets of chemically active elements, which are the additives, start interacting with each other.

Different categories of oil

For example, mineral and synthetic. One of the problems: mineral oil, unlike synthetic oil, does not have a stable viscosity. You have to use a suitable additive in it. It is not known how it will affect the synthetic component of the blend. Moreover, it is not clear how the additives will interact with each other over time.

engine oil

Therefore, it is strongly recommended not to mix different oils – it is difficult to predict what the result will be.

The main problems that may arise are the following:

  • Engine contamination – ring coking, slagging
  • Precipitation of additives or reduced efficiency Increase in oil viscosity up to its complete curdling and clogging of oil passages

Why is oil mixed?

Sometimes there’s a hard choice: you can’t refill the same oil immediately, so you take a risk and use a different one.

Globalization and unification can have a positive effect: bases and especially additives are produced by a small number of manufacturers.

This significantly reduces their compatibility problems, moreover – manufacturers are aware of this problem and are gradually trying to level it out.

General recommendations:

  • Never mix different types of oil (mineral and synthetic, for example)
  • As an extreme measure, you can mix fluids of the same manufacturer, but of different types.
  • It is desirable to change it and the filter later.

All the best!

Max Welder (rvneeded)

Max Welder (rvneeded)

Max Welder is a mechanic enthusiast. Currently, working at a small company. Experienced in electronics, car tools, and security systems. In his spare time, he writes articles for various blogs.

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