At What Percentage Should You Change Your Oil?

Oil reduces friction between rubbing surfaces and protects the engine from wear by creating a thin film. After the car has been idle, all the oil accumulates in the sump. When starting the engine and the first few seconds after it, the engine runs dry until the oil has been pumped through the whole system. During this time, it’s under a lot of stress.

Over time, the oil ages: additives wear out, oil oxidizes, and various contaminants accumulate. Accordingly, the oil performs its functions worse. It is when you must change it and remove all combustion products, spent additives, and residues from the engine. However, as to when exactly it happens, we’ll have to elaborate.

Why Do You Have To Change Oil?

Oil removes heat. The radiator and coolant perform this function, but oil removes heat by washing the friction points themselves. Some engine models even have special oil coolers for greater efficiency.

Oil protects against corrosion. Parts inside the engine work under exceptionally adverse conditions; they are exposed to high temperatures, significant temperature fluctuations, and combustion products. Agents and additives in the oil help avoid corrosion. They are different components of the oil. Agents are substances that change their properties when mixed with oil, while additives do not change properties but add new ones.

Oil removes products of combustion and engine wear. Combustion products (such as carbon deposits and soot) and the inevitable wear products of rubbing surfaces (such as metal dust and chips) accumulate in the oil. These products are then removed when the oil is changed.

How Often Do You Have To Change Oil?

The oil change interval is specified in each vehicle's instruction manual. Engine designers determine it by considering the engine characteristics and the vehicle's anticipated operating conditions. For this reason, recommendations on both oil selection and oil change intervals (as well as service intervals) may vary. For long and reliable engine operation, the oil should be changed as often as the car manufacturer recommends it.

The usually recommended period of oil replacement is 6 thousand miles. Manufacturers indicate intervals between 9 and even 12 thousand for some new car models. It means the manufacturer’s confidence in the car’s reliability and a direct reduction of maintenance costs for the owner.

Nevertheless, some experts advise keeping the oil change interval at 10 thousand km. A more frequent oil change benefits the engine, enabling the car to operate longer without any hitches after the warranty expires.

What Will Happen If You Don’t Change Oil For Two Years? 

So, with “old” oil:

• The lubricating properties deteriorate, which increases the friction between the moving parts. As a result, the load on the engine increases, which may result in the need for an overhaul. But if you only slightly neglect to change the oil, engine life will be reduced, it will overheat, and fuel consumption will increase.
• The oil is less effective at dissipating heat; as a result, the engine will overheat even more.
• Corrosion protection is reduced.
• Combustion and wear products accumulate inside the engine and clog oil passages, which can also result in an engine overhaul.

Summary

When buying a used car, it’s a good idea to change the oil immediately. The oil change period is described in the car's instruction manual. A more frequent oil change serves to only benefit your vehicle. So, it’s always a good idea not to delay an oil change and to get it done at the right time. 

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