engine oil myths

Common Myths and Facts about Engine Oil

In Engine Oil by Magnus SellénLeave a Comment

engine oil mythsIf you have taken your car for repairs you have probably heard some myths from the mechanic concerning engine oil.

Not knowing what is true and false may end up ruining your engine. Car models differ and this means how you use engine oil also varies.

Myths are closely held and it is difficult pinpointing where one came from. However, one needs to counter the myth with facts.

Common Myths

There are a lot of myths that are circulating about engine oil. Here is a list of the 12 most common myths, some more common than others.

1. Change oil after 3,000 miles

Most people will have an oil change during the next car service. You have probably been told that motor oil should be changed after 3,000 miles. However, this is not an accurate measure. Car models differ and depending on the motor oil a change can take place after 5,000 to 7,000 miles. You should check your car manual for an oil change or monitor the car diagnostic system.

2. You do not need to switch to higher quality oil if the car is running well

Low-quality oils do lots of harm to the car’s engine. While they are cheap you pay dearly through a ruined engine. inferior engine oils are loaded with contaminants that decrease the lubrication properties of the oil. Over time you will start spending more on repairs and eventually lead to engine damage.

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Switching to a high-quality engine oil does not affect your engine. In fact, it improves it.

3. Get new oil when going on a road trip

It is not entirely true that you need to change your engine oil when going on a long trip. If your car was due for service during the period then it is wise to have it changed before going for the road trip. However, if you did your service lately then you can always change the oil when you come back. You will need to observe the oil dipstick level. Add more oil if it is below the minimum.

4. Change oil if it’s black

New engine oil has an amber color. However, with continued usage, the oil gets contaminated with dirt as it runs through the engine. Engine oil having a black color is normal and should not be a cause for alarm.

5. You can continue using the oil filter after an oil change

engine oilThe oil filter and engine oil work together. The oil filter helps keep contaminants from your engine hence keeping the oil lubricating properties. It is advised that you change your oil filter with every oil change. If not your new oil will get contaminated faster.

6. You cannot switch back after using synthetic oil

Motorists often go for synthetic oil due to its resistance to high temperatures. It also has superior cleansing properties. After a while, you may want to change back to your original oil. As long as the viscosity of the oil matches you can always switch back and forth between the two oils.

You can contact your mechanic for the best synthetic oil. When people started using synthetic oil there were numerous complaints that it causes leaks. As the manufacturer’s improved the oil there was a reduction in such cases. However, you will hear complaints from older car models.

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7. “W” letter on engine oil packaging stands for weight

This is not true. Most people assume that the W means you have to use it on a certain car/bike weight. The W simply stands for winter.

8. Quality oil leaks in older engines

The myth is that if you have an older engine you should expect oil to leak from underneath the engine. This is not true. High-quality engine oil has been tested and if you notice leaks then your seals could be malfunctioning.

9. Engine oil is responsible for sludge

Sludge is caused by the accumulation of engine deposits, unburned fuel, and leaking coolant. High-quality oil cleans the engine off these contaminants and suspends it. If you notice an accumulation of sludge then you could be using poor quality engine oil.

10. You know it’s time to change engine oil through its smell

Engine oil is meant to clean the engine and when it is finished doing this it turns to black color. You should change the engine oil at constant intervals based on the oil manufacturer’s instruction. Not changing the oil reduces the oil effectiveness in lubricating and cleaning the engine.

11. Need to use detergent oil to break in a new engine

This is not a myth. Manufacturers suggest using detergent oil to break in a new engine. The reason for this is the new engine design and modern oil formulation.

12. Thicker engine oil is the best

This is not true. Thinner oil offers the best viscosity and is the most suitable for use in engines. It offers better lubrication and will help eliminate impurities in the engine. Thinner oil reduces friction between moving parts and is efficient due to the need for less energy to pump it through the engine parts.


Myths are created by people but they often do not have a factual basis. Many people do not understand the workings of engine internal parts and rely on the knowledge of their mechanics when changing car parts. Engine oil plays a vital role in keeping all engine parts lubricated and reducing friction.

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One common myth is the mileage needed for change in engine oil. Some will argue it should be 3,000 miles others 7,000 miles but you should change engine oil according to the manufacturer’s instructions. Engine oil turns to a dark color after use. This is due to the accumulation of sludge. This does not mean the oil is bad but it is actually doing its part. It is not a must that you replace engine oil whenever you are traveling long distance.

If you hard the service day near then replace it but if you had already done it then your car is ready for travel. However, do a service check before traveling. Check all car fluids are okay. This will include the coolant, brake fluid, and engine oil. Knowing when to change your engine oil helps keep your car running optimally.

The right engine oil keeps all moving parts from friction and overheating. Always use the recommended engine oil with a low viscosity.

12 Common Engine Oil MYTHS

Hello I'm Magnus, the owner and the writer of this website. I have been working with cars since I was 16 and I'm specialized with in-depth Automotive diagnostics. Also been driving drifting for the last 6 years. I'm here to give you answers to all your automotive questions and I hope that you enjoy our content.

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