Engine Lubrication Frequently Asked Questions
Basic Lubrication Goals and Features
1) What is the purpose of lubrication? The main goal of lubrication is to separate two surfaces to reduce friction. In addition, it lubricates surfaces, facilitates movement, and prevents corrosion/oxidation by forming a film. It also prevents the oil from mixing with fuel in the engine.
2) What does viscosity mean? Viscosity is the fluid’s resistance to flow. Therefore, it is the most important characteristic of fluids. Viscosity is a very critical factor that the consumer must consider first at every stage of lubrication.
3) What should be considered when changing engine oil? When changing the engine oil, observe the following: The oil should be warm. The vehicle must be on a level surface and in the stop position. Ensure that the old oil in the engine sump is fully drained and that the sump plug is reinstalled correctly.
Oil Loss and Deterioration
4) What is the reason for oil loss in the engine? The main reason is new technology engines where metals are designed closer together for high performance. This leads to oil consumption. Furthermore, not using oil of the appropriate viscosity or performance in the sump, and constantly running the vehicle at high RPMs are also reasons for oil consumption.
5) What does the darkening of engine oil mean? One of the important functions of engine oil is cleaning. A quality engine oil, thanks to its additives, absorbs soot particles formed in the engine and prevents them from sticking to metal surfaces. As the oil performs this cleaning task, it gets dirty and darkens. Therefore, dirty-looking engine oil indicates it is performing its duty well.
6) How do we know if engine oil has deteriorated? To definitively determine if engine oil has deteriorated, it must be subjected to physical and chemical analysis under laboratory conditions.
7) Can oil of a different brand be added when oil is low? First, the level of added oil should not exceed the normal level; otherwise, foaming and heating in the system may occur. The added oil must be of the same viscosity grade and the same API class. Be careful not to mix mineral oil with synthetic oil.
Oil Types and Performance Codes
8) What is the difference between synthetic oil and mineral oil? Synthetic-based oils are obtained through chemical processes. They are produced to perform lubrication in situations where other naturally structured oils cannot function. Synthetic oils are more resistant to higher or lower temperatures and high pressure than mineral oils.
9) What is oil performance and how do we understand it? We understand the performance of an oil from its API and ACEA values on the packaging. In the gasoline class, SL (July 2001) and in the diesel class, CI – 4 (2002) indicate the highest API performance level. For example, A3 indicates ACEA performance classes for passenger cars, B3 for diesel light commercial vehicles, and E4 for heavy commercial vehicles.
10) What does API SJ / CF mean? API (American Petroleum Institute) expresses the oil’s performance. ‘S’ indicates use in spark-ignited (gasoline) vehicles, and ‘C’ indicates use in compression-ignited (diesel) vehicles. In this case, since ‘S’ is listed first in the API SJ / CF example, the oil is primarily recommended for use in gasoline vehicles. The oil can also be easily used as a CF class oil in diesel vehicles.
11) What does 0W mean? The letter ‘W’ comes from ‘winter’. 0W means a very thin oil that exhibits a ‘zero’ number oil characteristic in winter conditions.
12) Does the type of engine oil change the oil change mileage? The oil change mileage for vehicles is determined solely by the vehicle manufacturers. Synthetic oils are more durable than mineral oils. Consequently, the oil being synthetic or mineral directly affects engine performance and protection. However, extending the oil change mileage without the manufacturer’s approval may not provide the expected performance and protection.
Foaming and Its Meaning
13) Why does foaming occur, and what is its harm to the engine? Foaming occurs as a result of sloshing in the sump due to the movement of the vehicle and the oil hitting surfaces inside the engine. If the engine oil has an insufficient anti-foam additive, the resulting bubbles burst on contact; thus, metal friction and wear begin. The creamy or mayonnaise-like appearance seen on the oil filler cap, commonly known, is not foaming. Instead, this occurs when water mixes directly with the oil or when oil vapor cannot escape and condenses into the oil due to temperature differences between day and night in older technology vehicles. This creaming has no direct harm to the engine, but it must be distinguished from true foaming.