The myriad types and brands of motor oil can give many a driver quite a headache. Which one to choose? Which brand is best? What should I consider when choosing the right oil?
First-time car owners are in the best position - they drove the car from the showroom with the oil already in the tank and with the instructions as to which oil to choose next time written down in the service booklet. The problem is, however, the situation when we buy a second-hand car and we do not really know what engine oil should we use.
In your choice, you should take into account not only the opinion of other drivers, as to the specific oil. It is important to look also at the parameters of a given oil described in technical sheets. One of such indicators is the viscosity index (VI), TBN, and the type of oil base.
The viscosity index
The viscosity index is a value that describes how viscosity changes with temperature. The higher the index, the better the oil's stability regardless of the temperature in the environment. The best choice, in this case, oils with a VI around 180.
The Total Base Number indicates the number of alkaline additives, i.e. additives neutralizing acid products of fuel combustion, e.g. sulfur. This number decreases with use, therefore choosing an oil with a higher TBN number will ensure a longer time of exhaust gas neutralization.
Usually, the oil base constitutes about 85% of engine oil volume. The remaining 15% are additives that are to enrich the oil. Engine oils can be divided into five groups. The first two are mineral oils, the third group includes synthetic oils, the fourth group includes synthetic poly-alpha-oleins (PAO), and the fifth group includes synthetic oils based on other technologies, e.g. esters. The last two groups are the so-called "true synthetics". They have much better parameters than the first three groups.
Remember to take into account the type of vehicle, its year, and driving conditions. The choice of engine oil is certainly not simple, but extremely important. Well-chosen oil will certainly contribute to the prolongation of the proper functioning of the engine and will allow you to cover many kilometers without any problems. You can always check your owner's manual to determine which type of engine oil you should use.