Will Synthetic Oil Make Your Engine Last Longer?

Vehicles are pretty significant investments, so it's a good idea to take steps to extend the life of that investment. Will using synthetic oil in your engine make it last longer? We have done some research on this topic and have the answers for you.

Synthetic oil is specially formulated to get the most out of your engine, and that includes keeping it running in good condition for the longest possible amount of time. Therefore, synthetic oil will typically lead to your engine performing better for longer.

The benefits of synthetic oil include:

  • Protects against high temperatures.
  • Combats the buildup of engine sludge.
  • Breaks down more slowly than conventional oil.
  • Effectively reduces wear on moving metal parts.

In this post, we will explore the benefits of synthetic oil in more detail and look at how it compares to the other available options. We'll also discuss how long synthetic oil lasts between oil changes, if synthetic oil can make your car faster, and if synthetic oil is appropriate for high mileage vehicles. Keep reading to learn more about this topic.

Motor oil poured to car engine, Will Synthetic Oil Make Your Engine Last Longer?

The Advantages Of Synthetic Oil

Let's take a closer look at the benefits of synthetic engine oil and how these benefits lead to extended engine life.

Thermal Stability

At high temperatures, engine oil can start to break down. This degradation is a type of oxidation, and it results in sludge and varnish deposits building up inside your engine. Synthetic oil is formulated to be thermally stable, which means that it is highly resistant to breaking down at high operating temperatures.

Additionally, this thermal stability has benefits at extremely low temperatures. Synthetic oil will not thicken as much as conventional oil does at cold temperatures, which means your vehicle will start easier under those conditions.

Sludge Fighting Capabilities

Another advantage offered by synthetic oil is that it contains high-performance additives to fight sludge buildup. These additives are usually some form of detergent or dispersant. They keep sludge and other contaminants suspended in the oil so that it doesn't gunk up your engine.

Lasts A Long Time

The advantages of using thermally stable oil go beyond reducing sludge buildup and performing better at extreme temperatures. Since synthetic oil is resistant to breaking down under high temperatures, it will last longer in your engine. Longer lasting oil means that you can go longer between oil changes without doing damage to your engine.

Reduces Wear

The thermal stability of synthetic oil also aids in the reduction of engine wear. If oil becomes thick and sticky, it becomes less effective as a lubricating agent, resulting in increased friction. This increased friction can wear down the internal components of your engine. Synthetic oil maintains its viscosity at different temperatures, which results in less friction on moving parts and, therefore, less wear on your engine.

The Downsides To Synthetic Oil

Synthetic oil may not be appropriate for all engines. Engines manufactured before 1990, especially ones that have been running on conventional oil for their entire life, do not always operate well with synthetic oil. Conventional oil flows slower, and this is often better for protecting and lubricating older or very high mileage engines. We'll discuss this in detail later on.

For newer vehicles, when compared to conventional oil or synthetic blends, the only real downside to synthetic oil is the price. However, when you consider the long term benefits of using synthetic oil as a means to extend the life of your engine, the price difference is hardly worth discussing.

With synthetic oil, you may spend more each time you get your oil changed, but you will need fewer oil changes over the life of the vehicle. Additionally, your engine will not accumulate as much internal sludge, and the moving parts will experience less wear. These benefits will reduce the need for costly maintenance in the future.

What Is The Difference Between Synthetic Oil And Regular (Conventional) Oil?

There are some key differences between synthetic oil and regular or conventional oil. Keep reading for a breakdown of the differences below.

Conventional Oil

Regular oil, also called conventional oil, is made from crude oil. Using a multi-step process refines crude oil into what we know as motor oil. Manufacturers will include additives and preservatives to make the oil work better in your vehicle and last longer. Each manufacturer includes its own mix of additives, but generally speaking, most conventional oils consist of some type of rust-inhibitor, antioxidant, detergent, and dispersant.

Check out this conventional oil on Amazon.

Synthetic Oil

Synthetic oil can be made from a variety of compounds, although many formulas are derived from crude oil. The real difference between conventional and synthetic is in the manufacturing process, which includes additional steps to refine and purify the base material before breaking it down into its base molecules. This process results in uniformly shaped and sized molecules, which means synthetic oil has fewer impurities than conventional oil. Having fewer impurities results in less friction, and therefore, better performance, especially at extremely high and low temperatures.

Fully synthetic oil contains the same types of additives as conventional oil, but these additives are higher performing and more effective. 

Check out this full synthetic oil on Amazon.

What Are Synthetic Oil Blends?

Synthetic oil blends offer a middle ground between fully synthetic and conventional oil options. If cost is a concern, you will find that while a synthetic blend is still more expensive than conventional oil, it is cheaper than full synthetic options. Another benefit is that you will get many of the performance and longevity advantages that come with using fully synthetic oil, albeit at a decreased capacity. In other words, it will perform better than conventional oil, but not as well as a full synthetic.

Check out this synthetic oil blend on Amazon.

How Long Does Synthetic Oil Last Between Oil Changes?

For most vehicles, the recommended interval for oil changes is every 5,000 miles, regardless of what type of oil you are using.

However, depending upon what type of synthetic oil you use, what kind of driving you're doing, and what kind of conditions you're driving in, it is possible to go longer between oil changes. Some full synthetic oils allow for 7,500 miles between oil changes.

Under the right circumstances, it is not unheard of to go even more than 7,500 miles between oil changes. With these increased oil change intervals, you should still change your oil at least once per year regardless of how many miles you drive. You should consult a qualified mechanic or technician to find out the best oil change interval for your specific vehicle.

Does Synthetic Oil Make Your Car Faster?

Many factors affect the speed at which your vehicle can travel, and the performance of your engine is one of them. Using synthetic oil won't boost your top speed beyond what is reasonable for your vehicle. However, it may make your engine feel like it has more power.

Synthetic oil has a consistently lower viscosity than conventional oil. A lower viscosity means faster-flowing oil, which results in your engine's internal parts experiencing less friction as they move. Less friction leads to higher performance and improved engine efficiency. 

Using synthetic oil to optimize your engine's performance can often result in more enjoyable driving experience. Still, it won't necessarily make your car noticeably faster in terms of miles per hour.

Is Synthetic Oil Better For High Mileage Vehicles?

Many people say that vehicles with more than 75,000 miles should not use synthetic oil. Some will claim that synthetic oil causes leaks in high mileage engines. Others say that synthetic oil can do damage to engine seals and other components in these more seasoned vehicles. Many of these claims are due to the myths that surround this topic.

While there is still a lot of debate among industry professionals, modern synthetic oil is perfectly safe for most high mileage vehicles. As long as you select the correct grade of oil for your engine, you should not encounter problems. Switching to a full synthetic or a synthetic oil blend in your high mileage vehicle can help restore lost performance and further extend the life of your engine.

Please note that a high mileage vehicle is not always the same as an older vehicle. A high mileage vehicle is any vehicle with 75,000 or more miles. An old vehicle is any vehicle manufactured before 1990. A vehicle may be both old and high mileage, but it isn't always both. As stated above, there are circumstances where older vehicles may benefit from sticking to conventional oil. You should consult a knowledgeable mechanic or technician to find out what kind of oil is best for your older vehicle.

Will Synthetic Oil Damage A High Mileage Engine?

One of the most common worries that people have about synthetic oil in higher mileage vehicles is that it will cause leaks or damage. Modern synthetic oil will not cause damage to your engine seals or gaskets. However, some engines do experience oil leaks after making the change to synthetic oil. These leaks typically happen because as the sludge clears out of their engine, old seals and gaskets that were plugged by sludge begin to leak. These components were already in need of replacement, and engine sludge simply masked the issue. 

Changing From Conventional Oil To Synthetic Oil In High Mileage Vehicles

Knowledgeable mechanics will often recommend more frequent oil changes after making the switch to full synthetic oil or a synthetic oil blend. The reason for this has to do with engine sludge buildup. Sludge and other contaminants become suspended in the oil when removed from the surfaces of your engine's components. Once the oil becomes polluted with contaminants, it needs to be changed. Since synthetic oils are more effective at removing engine sludge than conventional oil, you will need to change it more frequently at first as it cleans out your engine. After completing the initial cleanout process, you can change your oil at more regular intervals.


Synthetic oil can do a lot of really great things for your engine in terms of longevity and performance. Regardless of its composition, every synthetic oil will have the same general benefits. These benefits are improved thermal stability, reduced engine sludge buildup, longer oil change intervals, and improved engine protection. While using synthetic oil won't make your car faster, it can make it perform better, and ultimately extends the life of your engine.

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