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Can You Mix Car Engine Oils?


Car engine oil is just as essential as the engine, the most valuable vehicle component. As a car owner, you may have wondered, “Can you mix car engine oil?

Although it is possible to mix car engine oil in some circumstances, mixing different oil brands is not advisable because their various additives may not be compatible. And, likely, you won’t get the best car performance.

What is Car Engine Oil?

Car engine oil is a lubricant that protects the engine’s metal parts from wear and tear caused by constant friction. Another name for engine oil is motor oil. Different manufacturers use them interchangeably.

Car Engine Oil

What are the Types of Car Engine Oil?

There are four types of car engine oil:

1. Synthetic Motor Oil

Synthetic engine oil is an oil that passes through chemical engineering. As a result, the shape of its molecules is more consistent, there are fewer contaminants, and it has better properties than regular oil molecules.

It also works better than any other oil in extremely high and cold temperatures. Synthetic oil also has better functioning additives and is more resistant to oxidation.

2. Synthetic Blend Motor Oil

Synthetic blend engine oil is a car engine oil that combines a conventional base and synthetic oil. It contributes to improved oxidation resistance and performance, particularly at low temperatures.

3. High-Mileage Motor Oil

High-mileage engine oil has special additives that help decrease oil burn-off. It also aids in preventing oil leaks, which are common in older engines.

4. Conventional Motor Oil

Conventional engine oil is available in several viscosity categories and quality standards. Although it meets the minimum API (American Petroleum Institute) criteria your engine builder recommends, it lacks the additional performance that synthetic motor oils provide.

Is it possible to mix different engine Oil Brands?

Although we have given a simple explanation above, let’s take a deeper dive into the big question ‘can you mix car engine oils?’

male customer buying engine lubricating oil in the car supermarket

We already discussed the many types of engine oil, which comprise a base and a collection of additives that make up the oil base, and the distinctive features of the particular oil.

However, the bases of oils from other manufacturers are likely to be incompatible. Of course, this isn’t a problem.

But then, every brand has its process for producing bases, and some even employ different technology; therefore, these discrepancies have other physical qualities.

So, combining mineral and synthetic oils will not damage your car engine, but it will diminish the synthetic’s oxidation resistance and film strength.

When you mix synthetic oil with mineral oil, you get a synthetic blend, which is superior to mineral. The blend, however, will not provide you with all the synthetic advantages.

All companies have different ways of integrating antioxidants, anti-wear, and detergents in their compositions. Most brands update their formulation every year or every two years. As a result, ‌avoid mixing car engine oils from different brands to ensure the formulation’s most significant protection.

How Do I Mix Car Engine Oil?

If you must mix car motor oil for whatever reason, the safest option is to use oil from the same brand.

Also, look for a product with similar physic-chemical and performance qualities to the one you now have in your automobile engine; otherwise, the absolute viscosity will reduce. Except in extreme circumstances, we do not recommend it.

The Top Best Car Engine Oil from Different Manufacturers

The following are some of the best motor oil for your car engine.

 Synthetic Motor OilSynthetic Blend Motor Oil  Conventional Motor oilHigh-Mileage Motor Oil  
1Mobil 1 extended performance full syntheticPennzoil synthetic blend 5W-30Shell Rotella T4 triple protection conventional 15W-40Pennzoil platinum high mileage
2Valvoline advanced full synthetic SAE 5W-20Valvoline daily protection SAE 5W-30 synthetic blendValvoline daily protection non-detergent SAE 30 conventionalRoyal purple HMX high mileage
3Castrol edge 5W-40 A3/B4 advanced full syntheticQuaker state 550044965 motor oil, synthetic blend 5W-20Amazon basics conventional motor oil – 5W-30Mobil 1 mileage full synthetic motor oil 5W-30
4Pennzoil platinum full synthetic 5W-20Motul 5100 4T 15W50 synthetic blendShell Rotella T4 triple protection conventional 15W-40Royal purple HMX high mileage
5Amazon basics full Synthetic 5W-20Castrol 03096 GTX 5W-30 ultra-cleanPennzoil conventional 10W-30Castrol 03102 GTX high mileage 5W-30

Reasons ‌People Mix Car Engine Oil.

1. Emergency

Emergency is one of the key reasons ‌some people mix oil. When you’re going down the road, and your car runs out of oil, the leading oil brand you use isn’t available. In such a case, some people will use whatever brand of motor oil they can find at the time.

2. Cost reduction

Another reason people mix oil is to save money. Because of the high cost of oil, some car owners may not afford the particular brand they usually use. As a result, choose a less expensive oil brand.

3. Cost-effective blend

Some people combine conventional and synthetic oil to create a more efficient and effective blend. That may sound absurd, yet it is true.

However, because each brand formulates its oil with unique additives, combining oils may not negatively affect your car’s engine.

How to Change a Car Engine Oil

It is easy to change the oil in your vehicle. However, before changing the oil, whether at home or with a professional, check your car’s manual to see what oil the manufacturer recommends.


Required tools

  • an oil pan,
  • a socket wrench
  • a Filter wrench
  • latex gloves.

You can remove the filter manually or with the help of hacks. It is preferable to utilize the appropriate instrument for this job.

Use a socket wrench of ⅜-inch, the most common size for the drain plug. Although measures can be between  ¼-inch and ¾-inch.

Check your car’s manual for the location of the filter. Then use the proper oil filter; however, the spin-type is usually the most common type.

Procedure for Oil Change

The two methods for changing engine oil are the warm and cool methods. The warm method is the traditionally recommended method.

Drive around in your car until it reaches the ideal temperature. After that, park your vehicle on a flat surface and wait 15 minutes for it to cool down. It helps to thin the oil and make the flow more consistent.

The cool approach is also a viable option, particularly for older vehicles. It’s helpful because there’s no need to drive the car around, and there’s no remaining pressure between the sump and the filter, so the flow is more consistent.

Step 1

The first step is to park your vehicle on flat terrain. You won’t need to use a jack because the sump comes slanted toward the drain plug to help with oil evacuation.

You should keep the oil pan beneath the drain stopper, slightly off the center.

Step 2

You must undo the drain stopper at this point. Get a small bowl and pour the old oil inside the jar for the cool procedure. This will tell you if the coolant is leaking into the engine.

Step 3

Once all the oil drains out, remove the oil filter. While doing it, make sure you have a firm hold on the wrench and that it’s snug before turning it anti-clockwise to loosen the air filter.

Be prepared for the oil to burst forth forcefully. Wear a protective apron to keep the oil from splashing on you.

Step 4

Also, immediately before screwing the new filter back in, lubricate their fresh oil. After that, tighten it with a 34 twist.

However, tighten it to remove it when you need to change your oil again. Next, ‌replace the drain plug and repeat the procedure for the oil filter.

Step 5

Finally, pour half of the new oil into the engine and drive for around 5 minutes. Starting your automobile will assist the new oil spread out and prevent it from overflowing.

Close the oil filter lid and pour the leftover oil when your 5 minutes are up. Then, boom! You’ve finished changing the oil in your car.

Wrapping Up

Though mixing‌ oil or topping your engine oil with a different oil will not immediately harm your engine, it is never the best decision. When you combine two other ‌synthetic engine oils or oil of similar grade, weight, and viscosity, the additives in both oils may react negatively.

Mixing oil could have a long-term impact on your car’s engine. So, if possible, do not mix oil at all. Also, always consult your automobile manual to choose the best oil for your engine.

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