What does the color of your oil mean


Over time, the quality, consistency, and color tend to change on your oil-based lubricants this is because of many factors that directly “age” your oil. As a rule of thumb, color does not dictate the efficiency of oil. Color will change for a variety of reasons from heat, additives, and contaminants to something as simple as water and coolant so judging an oil’s efficiency on color alone is not possible. With that said let’s look into what we CAN learn from oil color.

First, color doesn’t necessarily mean anything. Oil can be very, very dark (black even) and still be effective. However, as a general rule:

  • New, clean oil is amber in color
  • As engine oil gets darker, it can indicate a) high heat, b) contaminants, or c) the presence of additives that cause the oil to darken during normal

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Next, let’s talk about the engine colors that indicate problems.

Milky, foamy, or cream colored oil can be an indicator of a head gasket leak if your exhaust is producing white smoke, or your vehicle is leaking coolant. Simply looking right under your equipment of vehicles oil cap should reveal if your equipment is suffering from milky or frothy oil. Typically this happens if the oil is exposed to water after raining or the equipment is not used long enough for the water on the engine to evaporate and burn off.

Thick, black, or very dark oil usually indicates that your oil has been exposed to dirt or dust contaminants that lead to a soot build up. Direct injection gasoline engines produce soot over time that causes standard motor oil to turn black and thick. Soot is a byproduct of incomplete combustion and since soot particles are less than one micron in size they typically do not cause much engine ware. The problem with soot happens when the soot particles begin to agglomerate into larger wear-causing contaminates. This is where the black thick texture may come from.

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Let’s also crack the myth that the color of your oil indicates when it is time to change your oil. It is very common for people to assume that there is a correlation between the color of oil, and the need to change the oil. This is not necessarily the case. Many of the changes and elements your oil is exposed to will change the color so there is no actual way to tell if your vehicle needs to be changed by just looking at it.

These are the big color indicators to look out for in your oils and lubes. As you have learned there is no sure-fire way to know what is wrong with your oil by just looking, however, these are some indicators that it may be time to replace or look into what is wrong with your storage. We hope very much that you have learned something new. If you are new to the SC Fuels blog, then consider subscribing for more useful and interesting topics!


-The SC Fuels Team.