Engine oil plays a critical role in the performance, durability, and efficiency of an internal combustion engine. It is far more than just a lubricant; engine oil reduces friction between moving parts, dissipates heat, prevents corrosion, keeps the engine clean by suspending contaminants, and contributes to fuel efficiency.
Despite the wide variety of vehicle brands and models available worldwide, the fundamental requirement remains the same: the correct lubricant. As of 2025, there are just over 100 original equipment manufacturers (OEMs), yet more than 5,000 vehicle models on the market. Each engine is designed with specific tolerances and operating conditions, which makes selecting the right engine oil essential rather than optional.
This article provides a comprehensive overview of engine oil types, viscosity grades, international standards, and practical guidance on choosing the right oil for your vehicle.
Understanding Viscosity and Engine Oil Grades
Before discussing engine oil types, it is crucial to understand viscosity, one of the most important properties of any lubricant.
What Is Viscosity?
Viscosity refers to an oil’s resistance to flow. In simple terms, it describes how thick or thin an oil is under certain conditions. Technically, viscosity is defined as the ratio of shear stress to shear rate, meaning how much force is required to make the oil flow.
Viscosity directly affects:
-
Cold-start protection
-
Oil flow through narrow engine passages
-
optional.
This article provides a comprehensive overview of engine oil types, viscosity grades, international standards, and practical guidance on choosing the right oil for your vehicle.
Understanding Viscosity and Engine Oil Grades
Before discussing engine oil types, it is crucial to understand viscosity, one of the most important properties of any lubricant.
What Is Viscosity?
Viscosity refers to an oil’s resistance to flow. In simple terms, it describes how thick or thin an oil is under certain conditions. Technically, viscosity is defined as the ratio of shear stress to shear rate, meaning how much force is required to make the oil flow.
Viscosity directly affects:
-
Cold-start protection
-
Oil flow through narrow engine passages
-
Film strength at operating temperature
-
Overall engine wear and fuel economy
Film strength at operating temperature
-
-
Overall engine wear and fuel economy

راهنمای گامبهگام ثبت شرکت در کانادا
دومینیکا بهترین گزینه برای اخذ پاسپورت دوم
اقامت فرانسه از طریق خرید ملک
تفاوت لمینت و کامپوزیت دندان
دندان قروچه چیست
ویزای تحصیلی روسیه
سایت وقت سفارت ایتالیا
دندان درد چیست
بلیچینگ دندان در شمال تهران
دندانپزشک زیبایی و ترمیمی
اوردنچر چیست
آموزش لیزر موهای زائد
درمان سریع دندان درد در شب
وقت سفارت سوئد