What is the purpose of engine oil in your vehicle?
The purpose of engine oil is to lubricate working parts of the engine. But why you say? Engines are made of metal. Metal on metal friction is not a good thing!
All engine oils are not the same
Different types of engine oil include;
- Conventional (also called mineral or regular)
The most modern oil. A thinner oil, where the molecules in the oil are specially made to meet the demands of modern day engine. Synthetic oil is designed to protect your vehicle under extreme circumstances. The longest lasting type of engine oil. It does not cause your engine to leak, however, because it is a thinner oil, it is easier to identify leaks in gaskets and/or seals.
A blend of mineral oil and synthetic oil. Semi-synthetic oil is usually cheaper than fully synthetic. The blend gives some of the benefits of synthetic oil ie. giving engine protection across a wide range of temperatures. It does not degrade as quickly as conventional/mineral oil.
Derived from crude oil. Most vehicles will run on conventional oil, however, it does not last as long as a synthetic or a semi-synthetic blend. It is cheaper in the short term however you will need it replaced more often.
What do the numbers on oil bottles mean?
There are also different ratings and viscosities of oil. Viscosity, “the state of being thick, sticky, and semifluid in consistency, due to internal friction.” Source 1.
An engine needs oils that will work in the cold and the hot. (something we know about in Wy). Oil becomes thinner when hot and thicker when cold.
You will see some numbers on a bottle of oil such as 10W30 or SAE 30. The ‘W’ means tested for winter temperatures. The lower the number in front of the ‘W’ relates to the lower the temperature the oil will flow at. This avoids a dry running the engine until the oil has warmed up to optimum operating temperatures. If you would like to know more in depth about how the oil is tested and where these numbers come from click here.
How do you know what engine oil do you put in your vehicle?
Always check the manufacturer handbook/manual that came with the vehicle, check the engine oil cap under the hood, or you can always give us a call. Whichever brand you choose, this link will help identify the rating you need, product-selector.
Lauren has been working in the automotive industry both in the U.K and in the U.S. for over 10 years. A car geek, photographer, big game chaser and bagpipe player, powered by coffee. Send your questions to: