Why Does My Oil Turn Black So Fast (Explanation Of The Secret)

Oil Turn Black So Fast

Jerry recently changed the oil to his BMW 328i to fuel his engine optimization and potential performance. But, after running the car for only 150 miles after the service, he noticed the oil’s color turned ample into black. 

Sigh! He asked himself; why does my oil turn black so fast?

It isn’t the scenery for Jerry; instead, most motorized vehicle owners face this. And that time, they become worried.

Relax; turning your engine oil black fast isn’t a sign of bad oil or immediate oil change. Generally, there are a few myths about getting the oil immature black. 

  • That can be the heat cycle of your vehicle. 
  • Generating soot due to  incomplete combustion
  • Deposits formulation into the oil 
  • Regular oxidation turns the oil black 

Do these three terms seem hard to understand? Will I need to explain? Keep reading 

My Oil Turn Black So Fast (Is There Anything To Worry)

First, it’s time to cheer that your engine oil turns black so fast. What do you think? I’m going to be mad, or I don’t have any specific knowledge about engine oil, or I’m directing you the wrong way. 

Wait, my friend. Turning oil black means it does its job as you desire. Sounds funny! 

Imagine, when you run your engine, its internal mechanism works to take you to your destination. Oil’s retaining properties work behind the mechanism to lube the parts and run the engine. So it’s pretty natural that minor contamination or debris mixed with the oil. When these are mixed into the oil, that makes the oil black. 

On the other hand, if the oil won’t turn black, something is wrong inside your engine that may lead to engine damage

So, hopefully, now you are transparent, there is nothing to be worried about your engine or oil’s working ability if the oil turns black so fast. 

Why Does My Oil Turn Black So Fast? 

Every engine oil (Synthetic, Petroleum, Diesel) sabotages, and there is some logical reasoning behind it. That I touched at the intro of this article. Now, I’ll explain all the critical things in simple words. 

Heat cycles 

Remember the driving schedule of your car. You probably drive the car to commute from your office to home, home to office, leave your children to their schools, your wife goes shopping, and so many other purposes. 

The engine won’t run all the time. Basically, for some hours, the engine works and rests for some hours in the parking lot. And it is continuously happening throughout its lifespan. 

So when the engine runs, it produces heat ranges 90°c to 104°c or 195°f to 220°f. When you stop the car, it cools down. 

This process of heating and cooling the engine is typically known as the “Heat Cycle.” This cycle has an impact on the engine oil, and for this, your oil will be black earlier. 

Building Soot In The Oil 

Though there is a myth that only diesel engines are associated with soot formation. That isn’t 100% right. The gasoline-direct-injection (GDI) engines also form soot because of incomplete combustion and cause the oil to black. 

When a human hair is around 70 microns in diameter, the soot particles are less than 1 micron. So, fortunately, these particles can’t wear your engine; they make the oil black. 

However, if somehow the soot forms large particles like 2 microns, the engine’s filter can catch them if you install a quality one. 

Oil Contamination 

Sludge, deposits, and carbon are the three culprits that contaminate the oil. When your engine operates, its metal parts come into contact and break tiny metallic particles from its components. These are so tiny that sometimes the oil filter can’t trap them. So over time, these will circulate into the oil and cause black crude. 

Normal Oxidation 

In general overview, oxidation is treated as a good sign for engine oil. But, regular oxidation also can make the oil immature and darker than ample. Oxygen molecules and oil molecules interact with each other during oil operations. So the oil’s chemical will break down, leading to faster black engine oil. 

Can You Drive With Black Engine Oil?

There are no hard and fast rules of driving your car with black engine oil, as it is correlated with many aspects. 

If the engine oil turns black within a few miles of running after the oil change. Undoubtedly you can drive your car with the black oil because it’s not too contaminated that it fails to lube your engine. 

You have to change the oil; on the flip side if the oil has crossed its regular oil changing interval based on your manufacturer recommendations. 

Otherwise, the black oil can cause your engine failure, seizing, or even permanent fatal breakdown. That leads you to invest a considerable amount in car repair. 

How Long Does It Take For Oil to Turn Black?

First, the oil contains many additional additives and detergents in its formulated chemistry. So it can turn into slight discolor because of these remnants. 

However, there are so many variables to determine how long the oil takes to turn black. I’ll segment the variables into 3 parts to make them understandable for all levels of oil users. 

Segment 1: Running miles that turn the oil slightly black

Though your engine is diesel powered, with a new filter and very low mileage, it turns a bit black within 20 to 50 miles of running. It may even be faster than the mentioned mileage. But, in this case, you won’t have to change the oil, as the oil can fine-tune your engine according to its requirements. 

Segment 2: Running miles that turn the oil completely black

Though your car is new and comes with a modern engine with 150k or 200k mileage efficiency. If the engine consumes more than 1 quart of oil to run 3k miles, the oil will turn completely black and lose its viscosity and operation capacity. In that case, you immediately have to change the oil to keep your engine running at its maximum performance. 

Segment 3: Oil quality and weather conditions 

There is no alternative to admitting that your local weather conditions and the oil quality also play a vital role in defining how fastly or slowly the oil will turn black. 

If you use the right oil based on your vehicle engine requirements and the weather condition. The oil takes more time to get black than poor oil and driving under harsh weather conditions. 

So, most professionals suggest checking the oil color once a month. It’ll help you determine whether your car needs an oil change or not. 

How To Check Oil Color? 

I have talked about one particular thing: black oil. But, until you check the oil color, you can’t define the color of your engine oil. Here is a simple process and a litmus test to know your engine oil color. 

The way you should follow

  1. Stop your car’s engine and park it on the even and flat ground.  
  2. If the engine runs for miles, let it sit for at least 15 minutes to cool down. 
  3. Arrange a clean rug in your arm’s reach. 
  4. Open your car hood and detect the dipstick. 
  5. Pull out the entire dipstick and wipe it from one end to another with the clean rug. 
  6. Examine the oil’s quality and color.  
  7. If you notice the oil looks ample in color, it is still good in quality and fresh. 
  8. If the oil looks slightly black, it indicates it perfectly operates and won’t require an oil change. 
  9. If the oil looks gunk like black, it means you should change the oil. 
  10. If you find tiny metal specks on the rug, that may indicate internal damage to your engine.


Why does diesel engine oil turn black quickly? 

Diesel engines come with an increased combustion temperature in its cylinders. The diesel burns more efficiently and reduces exhaust emissions released due to this combustion temperature. This procedure fuels the contamination of the diesel oil. That’s why diesel engine oil turns black faster than gasoline engines. 

Synthetic oil turns black quickly?

There is a massive difference between the consistency of synthetic and conventional oil. Synthetic oil turns black faster due to thinner viscosity, dirt particles in the engine, formation of carbon, and dirty air. 

Motorcycle oil turns black quickly?

Building deposits and sludge, air debris, oxygen molecules, and so many other things are the reasons for quickly turning your motorcycle engine oil black. 


Faster turning your engine oil black isn’t a matter of concern; instead, it’s an indication of incredible operations of your oil. Use the best oil for your engine based on company requirements, take care of your engine, and keep a keen eye on regular oil change intervals.  Following these basic but effective tactics will help you improve your engine life with peak performance.

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