Oil is the lifeblood of the engine. It lubricates components, ensuring that those many moving parts work smoothly together; it draws heat away from the blazing environment of the engine block and head and thanks to additives included in its mix, prevents sludging and other nasties from fouling the engine. In short, no car is going far without the right amount of the right sort of oil flowing through it.
Oil comes in a variety of types – it can be regular mineral/conventional oil, synthetic, or a blend of the two known as semi-synthetic – and comes in various grades of viscosity. Viscosity is important, as the thicker (more viscous) the oil, the slower it flows and the more work some components must do to move through it. The thinner the oil, the less lubrication it provides. It’s useful to note that oil thins as it heats up and thickens as it cools.
Different types of engines require different levels of oil viscosity to be at peak performance and these viscosity grades are represented by two numbers and the letter W – 10W40, for example.
The ‘W’ stands for Winter and the number that precedes it (the 10 in 10W40) relates to the oil’s viscosity at 0 degrees Fahrenheit. The lower that number, the better it is at keeping its useful viscosity in the cold. The second number (the 40 in 10W40) relates to the oil’s viscosity at 212 degrees Fahrenheit (100 degrees Celsius). The higher the number, the more it can keep its useful viscosity at high temperatures.
Manufacturers recommend a specific grade of oil for their vehicles. They may also recommend it be mineral/conventional, synthetic or a blend. This information can be found in the manufacturer’s/owner’s handbook.
It’s important that the right grade and type of oil be used. Using the incorrect oil can lead to increased wear and tear to engine components and a shorter engine life. Stick to the manufacturer’s recommendation. However, if there is some uncertainty about what that is, a local qualified mechanic will know which oil is right for any particular vehicle.
Want to learn more?
MTA Queensland’s Vehicle Maintenance course is designed for those who are interested in gaining valuable information and learning good practices for everyday vehicle use. The result: a safer journey with fewer breakdowns and repairs. If you have ever wanted to learn how to carry out preventative maintenance, then this course is for you.
17 March 2020
Please note the information contained on this page is general in nature and does not take into account your specific needs or circumstances. You should consider whether the information is appropriate to your needs, and where appropriate, seek professional advice.