How to choose the right engine oil for your car

Although there are many types of oil, the only oil of concern to you is what is prescribed in your car’s manual. But it is essential to know what the different oils are so that you can purchase oil at a garage that matches the oil prescribed by your car’s manufacturer.1

Your car’s manual1

The manual will indicate the type of oil in the usual format, such as 10W-30. The latter number describes the oil’s thickness. Whatever oil brand is available at a garage, ensure that the starburst symbol is shown, as this means the oil was tested by the American Petroleum Institute (API). There will also be the designation ‘SP’ for petrol engines and CK-4 for diesel engines on the oil can. Other similar designations are currently SN, SM, SL and SJ for petrol engines, and CJ-4, CI-4, CH-4, and FA-4 for diesel engines.

What about the oil’s thickness? 1

Viscosity describes the thickness of the oil. Most engine oils are rated on their viscosity at 0 degrees Fahrenheit (-17,7778 degrees Centigrade). This viscosity value is written before the letter ‘W.’ The viscosity at 212 degrees Fahrenheit (100 degrees Centigrade) is the value written after the ‘W’.

Thicker oil protects the engine better1

As the oil heats up in the engine, it becomes progressively thinner and thicker when it cools. A thicker oil provides a better layer of protection for moving engine parts than a thin, runny oil. That’s why additives are included with oil to resist excessive thinning when hot. The higher the second number, the greater the resistance of the oil to thinning (e.g., 10W-40 compared to 10W-30).

What about thick oil at low temperatures? 1

The converse is also true: additives are included in oil to resist its thickening at low temperatures. Increased thickness of the oil can cause the engine to labour harder to move the engine parts, affecting the fuel economy.

How can you distinguish between conventional and synthetic engine oil? 1

Premium conventional oil is used for new cars. Manufacturers designate a 5W-20 or 5W-30 for cooler climates, while 10W-30 is recommended for normal and higher temperatures. Remember to change the oil and oil filter regularly.

Full synthetic oil is used by high-tech engines and contains many synthetic additives. This type of oil shows an improved flow at lower temperatures and keep maximum viscosity at higher temperatures. However, these oils are expensive, and most engines don’t need them.

Disclaimer

This article can only provide information because car insurance is complex. For this reason, you need to first consult a certified financial advisor for professional advice before buying car insurance.

Sources:

1. 1. How to Pick the Right Motor Oil for Your Car