Viscosity is the property of oil that determines its fluidity. It should be sufficient for all the moving parts of the engine to be optimally lubricated in all operating conditions. The level of viscosity changes depending on temperature. In particular, it decreases as the temperature increases. That is why it’s necessary to start the engine and let it run for a few minutes to make it easier to drain used oil.

When choosing the oil, make sure to follow the recommendations from the car manufacturer. There are three main groups of motor oils: Mineral: This type loses its properties when the temperature is too low or too high, but is affordable. Semi-synthetic: This is more efficient when starting the engine cold. It is suitable for both petrol and diesel engines, including higher-power ones and those equipped with a turbocharger. Perfect for vehicles with high mileage that are used at an ambient temperature of no lower than −20°C. Fully synthetic: This protects the engine from wear and withstands significant temperature fluctuations, has a long service life and helps save fuel. It is the most expensive type.

The service life of the motor oil depends on the operating conditions and technical condition of the specific vehicle.Driving off-road, towing a trailer, an aggressive driving style, and frequent short trips lead to accelerated degradation of any type of motor oil.If the vehicle has a high mileage, the oil, regardless of its type, should be replaced more often than specified in the car owner's manual.

The replacement interval is defined by the car manufacturer and specified in the car owner's manual.It is calculated based on the average indicators: driving in a region with a moderate climate, on high-quality roads, and making long-distance trips.When making short-distance trips in winter, the engine does not have enough time to warm up to the operating temperature.Moisture accumulates on the walls of its cylinders, increasing the risk of corrosion. The sediment formed clogs the oil channels and obstructs the free flow of oil.When driving on dusty unpaved roads, fine slurry may also form. In such conditions, it is recommended to replace the motor oil together with the filter at least once every 6 months or 6,000–8,000 km.

Cleaning the engine oil system is necessary only if the engine is heavily worn or the vehicle has a high mileage.

Accelerated oil darkening is normal for diesel engines. It is caused by the soot in the oil left after fuel combustion.In petrol engines, it is a sign of deposit formation which means that the vehicle has been used in harsh conditions.It can also occur because of aggressive driving or engine overheating due to a cooling system malfunction.If you noticed that the motor oil in your petrol-powered vehicle has darkened quickly, visit a garage for engine diagnostics.

No. You can only add another type of oil in case of emergency when there is no other option available.

The quality is determined according to three classifications: American API, European ACEA, and international ILSAC. In addition, the distinctive properties of an oil are determined by the quality of the raw material it is made from.Synthetic motor oils are high quality and expensive.They are followed by semi-synthetic oils.The cheapest option is mineral products made of oil.

Many modern oils are universal, but there are special products for diesel engines. These usually have enhanced antioxidant and cleaning properties.

This is the viscosity motor oil classification developed by the Society of Automotive Engineers. The products are divided into winter, summer, and multigrade types.Winter oils are indicated with a certain number and the letter W (for winter): 0W, 5W, 10W, 15W, 20W, 25W.The lower the number before the letter W, the more fluid the oil will be at low ambient temperatures.Summer oils are marked with SAE and a number: SAE 20, SAE 30, SAE 40, SAE 50, SAE 60.The higher the number after SAE, the higher the oil viscosity at the engine operating temperature.All multigrade oils are marked with a combo of summer and winter oil symbols: SAE 0W-20, 0W-30, 5W-30, 5W-40, 10W-40, 15W-50, etc.

This is the motor oil service classification developed by the American Petroleum Institute. It divides the products into two main categories: S (service) for petrol engines. C (commercial) for diesel engines. The next letter specifies the grade of the product. The farther it is from the beginning of the alphabet, the higher the oil quality is (e.g. oils marked SL have a higher quality than those marked SJ). The numbers next to the oil grade specify the engine type: 2 for 2-stroke engines; 4 for 4-stroke engines.

This is the service classification of motor oils developed by the European Automobile Manufacturers Association. It places high demands on products. In this system, classes are indicated with a letter and specify the applicability of oil for certain types of engines: A – for petrol engines. B – for diesel engines in passenger cars and minivans. C – for engines with catalytic converters. E – for diesel engines in heavy-duty vehicles. The number after the letter specifies the performance characteristics of the oil. The larger it is, the higher the quality. Low-viscosity, fuel-efficient oils are marked as A1/B1, where ""1"" does not indicate low performance characteristics.