Whether you own or lease a car, it’s important to understand the ins and outs of your oil. Different vehicles will use different types of oil, and using the wrong type can be harmful to your engine. Here’s an explanation of what motor oil is, what it does, and what aspects of it matter for the beginning car owner.
What Is Motor Oil?
Two components make up the majority of motor oils on the market: additives and base oils. These two components work together to create the final oil product that is placed in your engine. A good analogy is coffee; the base oil is the water, while the additives are the coffee beans. When you mix them, you get a delicious caffeinated beverage.
The largest part of the motor oil is made up of the base oils. These oils are what’s used to lubricate the internal moving aspects of the engine. They also absorb engine heat and help to seal the piston rings.
Base oils can be comprised of a variety of materials, most often:
- Materials that have been chemically synthesized
- A blend of both petroleum and chemically synthesized materials (commonly called synthetic blend or semi-synthetic)
A petroleum base oil has been refined from a crude oil source. When you use crude oil, there will be contaminates such as oxygen, nitrogen, sulfur, and small traces of metal components. These contaminates can’t be fully extracted through the refining process. When oil is refined, the different molecules are separated by their weight. This leaves all the molecules that weigh roughly the same as the oil molecules, even if they’re a contamination.
Synthetic oils are different because they’ve been engineered by humans. Since they aren’t pulled from a natural source, they don’t have any contaminates. They’ve been designed to include beneficial molecules and nothing else. The versatility and the uniform molecules allow the oil to provide better friction, better fuel efficiency, and better performance in extreme temperatures.
Additives do everything that the base oils can’t accomplish on their own. They provide anti-foam, acid neutralization, anti-wear, corrosion protection, dispersancy properties, detergency, and viscosity maintenance. Some chemical additives include boron, phosphorous, and zinc. The toughest part of oil formulation is striking the right balance between the base oils and the additives.
The Purpose of Motor Oil
Whether you use natural or synthetic oil, motor oil is designed to fit these purposes:
- It minimizes friction and wear on the engine by separating components that come into contact with each other
- It cleans the engine by suspending any contaminates inside its fluid or preventing the adherence of contaminates to an engine component
- It cools the engine by reducing the heat and friction in the engine
- It dynamically seals locations such as the cylinder interface and piston ring, which allows combustion gases to stay in the combustion chamber
- It dampens mechanical shock by dispersing shock waves over a large area rather than concentrating them in one place
- It protects the engine components from corrosion by neutralizing corrosive contaminates or creating a barrier between potential contaminates and the engine components
- It transfers energy between different engine components
Viscosity and Your Motor Oil
When people talk about viscosity, they mean the amount of resistance that the oil has to flow. Viscosity is the most important aspect of an oil. Viscosity also changes with the temperature; oil is thinner when it’s hot, and it thickens when it cools down.
Oil needs to be cold when it lubricates the engine during the initial startup, but it needs to be thick enough for engine protection when the engine has a high temperature. This means that you need to strike a balance by finding an oil with a viscosity that can work both hot and cold. The type of viscosity you need will vary depending on your environment; generally, people in hotter environments need a thicker oil.
Viscosity is measured by grades. These grades explain when the oil reaches a temperature that causes the viscosity to fail. You should find out what viscosity is best for your environment.