What is the Difference Between Oil Types?

September 14th, 2023 by

Every driver knows that motor oil is essential for a vehicle, but not everyone understands why. Regular maintenance is vital if you want to keep your car or truck in top shape. Your car is unlikely to need major servicing on a routine basis, but it will need oil changes to operate at peak performance. If you don’t understand the various types of motor oil and how they differ, go to or call your local service center or keep reading to find out more.

The Basics of Motor Oil


It’s important to understand the role that motor oil plays in your car’s performance. Internal combustion engines generate a huge amount of heat and include many moving parts that create friction. Over time, heat and friction can cause different parts of a vehicle’s engine to break down or malfunction. Motor oil helps lubricate your car’s engine, decreasing friction and excess heat and preventing wear and tear.

Here’s a more detailed breakdown of how motor oil works:

  • It provides a thin layer between moving parts, allowing them to move smoothly with decreased friction.
  • Decreased friction prevents the breakdown of engine components and reduces the heat generated by the engine.
  • A layer of lubricant disperses shock when components come into contact, reducing wear and preventing damage.
  • Motor oil suspends contaminants such as dust, dirt, and metallic particles, preventing them from accumulating on engine parts and causing wear.
  • Oil and other lubricants can absorb heat from engine components and disperse it as the fluids circulate.
  • Some motor oils can dissolve contaminants, reducing the overall amount of particulates in your engine.
  • The oil prevents corrosion creating rust in the engine by providing a dynamic barrier and dissolving or otherwise neutralizing corrosive elements.

Not all motor oil performs each of the above functions. Different oil grades include a range of additives that determine performance. The exact role of your car’s oil will depend on its recommended oil grade.

No matter what oil grade your car needs, it’s important to get regular oil changes. As time passes, the oil in your car’s engine will begin to break down and become contaminated. This decreases its effectiveness and can lead to overhearing, decreased fuel efficiency, and damaged engine components.

Understanding Viscosity

Every type of motor oil has an assigned grade that relates to its viscosity. Viscosity relates to the thickness of the liquid, and it’s determined by the liquid’s ability to resist flow. For example, water has a very low viscosity, while molasses has a very high viscosity. This property isn’t stable, so fluids lose viscosity at high temperatures and become more viscous at low temperatures. A suitable motor oil is viscous enough to lubricate a car’s engine at high temperatures and thin enough to function in cold weather conditions.

When referring to motor oil, people may use the terms grade, viscosity, or weight interchangeably. This property is measured based on a standardized scale developed by the Society of Automotive Engineers (SAE).  When you see the letters SAE in the name of your motor oil, it simply refers to this standard classification.

Motor oil can be either straight weight or multiweight. Straight-weight oils have a single viscosity grade but aren’t very common anymore. Nowadays, multiweight or multigrade motor oils are far more common. They have two grades — one for high temperatures (212 degrees Fahrenheit) and one for low temperatures (zero degrees Fahrenheit). The label on this type of oil shows two numbers. The first refers to the viscosity at low temperatures, and it’s followed by the letter “W” for winter. The second number indicates the oil’s viscosity at higher temperatures. For example, one type of oil you might encounter is SAE 5W-30.

Conventional vs. Synthetic Oil

When shopping for motor oil, you may encounter conventional and synthetic varieties. Conventional oil is simply refined crude oil and was more common in the past. Although it’s not ideal for newer cars, it may be necessary to use conventional oil if you drive an older car. These vehicles were not designed to use synthetic oil and may not perform well if you use it.

Synthetic oil is by far the most popular choice for newer vehicles. It’s made from refined petrochemicals that imitate crude oil. The two main types of synthetic oil are synthetic blend oil and fully synthetic oil. Synthetic blends combine a base of conventional oil with other chemicals, while fully synthetic oils don’t contain any conventional oil at all.

The addition of alternate chemicals gives synthetic oils a range of advantages over conventional varieties. Manufacturers can add detergents, corrosion inhibitors, antioxidants, anti-foam agents, viscosity improvers, and other additives. These chemicals help clean the engine, prevent corrosion, and enhance performance. In most cases, a synthetic blend will have 10%-30% additives and 70%-90% base oils.

Synthetic Blend and High-Mileage Oil

As mentioned above, synthetic blend oils use a mix of conventional base oils and synthetic oils. In addition, they often contain other additives for increased performance. Compared to conventional oils, synthetic blends offer greater corrosion resistance and a lower risk of residue buildup.

High-mileage oil is specially formulated synthetic oil designed for older cars and vehicles with more than 75,000 miles. You can think of this oil as medicine for older engines, as it includes a range of additives that combat leakage, excessive oil consumption, and engine wear. The main feature of these oils is that they include seal enhancers. These additives combat gasket and O-ring degradation by causing these parts to expand. This reduces leakage in the engine, increasing performance and decreasing oil consumption.

Choosing the Right Oil for Your Vehicle

The first thing to do when looking for motor oil is to consult your vehicle’s owner’s manual. In most cases, the manufacturer will recommend a single grade or several for different climates. While staying close to these parameters is important, you can adjust the oil you use based on where you live. If you experience harsh winters, look for an oil with a low winter viscosity, such as 0W or 5W.

Quality Oil Changes at Our Service Center

Now that you know a bit more about motor oil, it’s time to put your knowledge into practice. Every vehicle needs regular oil changes, so you won’t have to wait too long. If you’re ready to get an oil change today, look no further than #1 Cochran Chevrolet in Youngstown, Ohio. You can set up a service appointment easily online, and our expert staff will have you in and out in no time. Schedule your appointment today and extend the life of your car.

man refilling motor oil on car engine bay by Tim Mossholder is licensed with Unsplash License

Posted in Tips