Which is better: synthetic or mineral?

So, the main operational difference between synthetic and mineral engine oil is a higher level of stability in its properties and characteristics across different temperatures and over long use.

What does that mean for the average driver? Three things.

First — synthetic engine oil is, in principle, less afraid of low temperatures and overheating.

Second — synthetic oil holds on to its properties longer over the course of use.

Third — some engine oil parameters, mandatory for many modern engines, simply can't be achieved on a fully mineral base. Viscosity is a good example of that.

That said, it's important to remember that everything in this world is relative, so using synthetic engine oil specifically is by no means always a pressing necessity. For instance, everyone knows platinum conducts electricity better than copper, but that doesn't mean you need platinum wiring in your home, since the properties of copper wiring are entirely sufficient for connecting and running household appliances. In a word, good enough is the enemy of better.

In some cases it's actually the opposite — synthetic oil is contraindicated for the engine — this mostly concerns high-mileage engines.

So, if the region where you run your car doesn't typically see winter temperatures drop below, say, minus 15-20 degrees Celsius, there's no pressing need for you to use synthetic engine oil, provided, of course, that every other property of the oil suits your engine. You'll simply have to change a mineral or semi-synthetic oil a little more often than you would a synthetic one. In that case, there's no harm whatsoever to the engine from using mineral or semi-synthetic engine oil.

Read on: what are hydrocracked oils, and should the word "hydrocracking" scare you?