Homepage

Blog

Choosing the Right Motor Oil Viscosity for a Long-Lasting Engine

LONG

08/02/2025

0 Comments

Car

Choosing the right motor oil viscosity is crucial for ensuring optimal engine performance and longevity. Using the wrong type of oil can lead to serious problems, ranging from reduced engine efficiency to major damage.

Understanding Motor Oil Viscosity Grades

Motor oil viscosity grades, usually printed clearly on the packaging, are codes that indicate the oil’s thickness and other properties. Understanding these grades helps you choose the most suitable oil for your vehicle’s engine.

Viscosity: The Core Factor

Viscosity refers to the oil’s resistance to flow. The viscosity grade typically consists of two numbers separated by the letter “W,” such as 5W-30.

The number before “W” (Winter): Indicates the oil’s viscosity at low temperatures. The lower the number, the thinner the oil at cold temperatures, allowing for easier engine starts in winter.
The number after “W”: Indicates the oil’s viscosity at high temperatures (100 degrees Celsius). The higher the number, the thicker the oil at high temperatures, providing better engine protection during high-speed operation.

API and ILSAC Standards

In addition to viscosity, motor oil specifications also include quality standards set by the API (American Petroleum Institute) and ILSAC (International Lubricants Standardization and Approval Committee).

API: Uses the letter “S” for gasoline engines and “C” for diesel engines, followed by another letter indicating the performance level. For example, API SN Plus is a higher standard than API SL.
ILSAC: Uses the letters “GF” followed by a number indicating the performance level. For example, ILSAC GF-6A is the latest and higher standard than ILSAC GF-5.

Different types of motor oil

Choosing the Right Motor Oil Viscosity

To choose the correct oil viscosity, consult your vehicle’s owner’s manual or the manufacturer’s website. Here are some important considerations:

Climate: Choose low-viscosity oil (e.g., 0W-20) in cold climates and higher-viscosity oil (e.g., 10W-40) in hot climates.
Operating Conditions: Vehicles frequently driven under harsh conditions (high temperatures, heavy loads) should use higher-viscosity oil.
Engine Age: Older engines may require higher-viscosity oil to compensate for larger clearances.

Benefits of Using the Correct Motor Oil Viscosity

Increased Engine Lifespan: Suitable oil provides effective lubrication, reducing friction and wear, thus extending engine life.
Fuel Economy: Thinner oil allows the engine to operate more smoothly, improving fuel efficiency.
Reduced Emissions: High-quality oil helps minimize harmful emissions.

“Listen to your engine, it will tell you!” – Mr. Nguyen Van A, Automotive Mechanical Engineer

Mr. Nguyen Van A, an automotive expert with over 20 years of experience, shares: “Using the correct motor oil viscosity not only helps the engine operate more efficiently but also prolongs its lifespan. Always follow the manufacturer’s recommendations and change the oil regularly to ensure optimal vehicle performance.”

Car oil change

Conclusion

Motor oil viscosity plays a vital role in engine performance and longevity. Be a smart car owner, choose the right type of oil, and change it regularly to protect the “heart” of your vehicle.