High Mileage Oil Vs Synthetic Blends

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For most car owners, it’s usually confusing to pinpoint the best type of oil for their vehicles. The confusion often kicks in after they’ve driven the car for a long time, covering tens of thousands, or hundreds of thousands of miles.

It is argued that high mileage vehicles should use high mileage oils, instead of fully synthetics or synthetic blends. What’s our take on this? Let’s compare high mileage oil vs synthetic blends.

Many people have been talking about “high mileage oils” for a long time, but they aren’t so different from the regular engine oils you know.

What Is High Mileage Oil?

High mileage oils simply refer to those motor oils that contain more specific additives that are believed to be the best fit for old or high mileage engines.

The additives (conditioners, seal swells, antioxidants, detergents, etc.) available in high mileage oils help to prevent wear and tear in older engines.

However, the term “high mileage” is literally a marketing trick. Engine oil manufacturers are using this term to sell out their oils at a seemingly higher cost than basic motor oils.

Although high mileage oils contain more specific additives for older vehicles, synthetic oils are still good for old and new vehicles.

Read Also: Can Different Weights of Oil Be Mixed Together?

What Is Synthetic Blend?

What Is High Mileage Oil

Synthetic blend is simply a mixture of fully synthetic oil with regular/conventional oil. There are companies that manufacture synthetic blend oils; however, individuals can do mixing themselves. Well, this type of oil isn’t bad for any engine (whether new or old).

But, when you use synthetic blends on your car, the engine won’t get much from the contradicting additives present in the two oils. This implies that synthetic blends are less effective than full synthetics or even some conventional oils.

Now, comparing high mileage oils with synthetic blends, which is the best to use in your car?

High Mileage Oil Vs Synthetic Blends | Any Differences?

First Point

Both high mileage oils and synthetic blends are gotten from mixing two different oils. However, while synthetic blends are simply a mixture of full synthetics with conventional oils, high mileage oils are mostly gotten from mixing synthetics with another petroleum-based oil and adding specific additives.

Second Point

High mileage oils are advertised to contain additives that help reduce engine wear, as well as provide anti-ageing benefits. Also, high mileage oils tend to contain conditioners believed to help rejuvenate seals and checkmate oil leaks in older engines or high mileage.

In contrast, synthetic blends aren’t advertised to contain such additives that are available in high mileage oils.

However, this doesn’t mean that synthetic blends don’t contain additives that are fit for older engines with higher mileage – they are just not advertised to have them.

Third Point

Typically, high mileage oils are costlier than synthetic blends. Some people believe that the added price means the oil is best for their high mileage engine.

But this is not true; what your car needs is a free-flowing, clean oil – it doesn’t necessarily have to be a particular type.

Fourth Point

Both high mileage oils and synthetic blends can be used for any engine (whether new or old). The additives are generally safe for all kinds of engines.

So, whether your odometer is reading less than 50k miles or over a 100k miles, either of these oils is yet good for your engine.

High Mileage Oil And Synthetic Blends | Which Lasts Longer?

What Is Synthetic Blend

If you drive less than 7,000 miles in a year, then you should change oil annually. The concern about how frequently you should change your engine oil kicks in when you drive several miles in a year. Generally, it is recommended that you change the oil after about 5,000 – 7,000 miles.

But, based on several factors, some people wait until after 10,000 miles before changing oil, while there are extremely careful drivers that would change their oil every 3,000 – 5,000 miles.

Between high mileage oils and synthetic blends, it may be difficult to pinpoint which of these two would last longer.

Furthermore, high mileage oils are recommended for cars with over 75,000 miles; this is because the engine of such cars may have potential leaks and have accumulated lots of deposits.

The additives in high mileage oils will perfectly clean such engines, as well as prevent leaks and other potential damages that may result from a severally tortured engine. For this purpose, high mileage oils cost more than synthetic blends.

If your car is still new, you should stick with the recommended oil from the manufacturer; else, you may void the warranty when things go wrong too quickly.

Synthetic blends also help to clean sludge, grimes, and other deposits that may accumulate inside an engine. They are also good for old/high mileage engines.


Both high mileage oils and synthetic blends are good for all engines; however, high mileage oils are a better option for older cars (with high mileage) due to the special additives they contain.

If you’re not willing to spend more on motor oils, synthetic blends are okay to use, and if you wouldn’t mind spending more dough, synthetic blends are yet good.

So, when comparing high mileage oil vs synthetic blends, the actual difference is the additives used, and sometimes, the price.

Key takeaway: not using high mileage oil in a “high mileage” vehicle doesn’t mean your engine would leak. Also, using synthetic blends on high mileage vehicles poses no harm to the engine. At all times, you should use the most suitable oil for your engine.

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