What Is CF4 Oil? [A Practical Answer for You]

CF4, CI4, CF, and CI are the categories laid down by API (American Petroleum Institute). These grades classify various generations of diesel engine oils. Moreover, the diesel oil compression ignition base C. Like, A, B, C, F, or K, signifies the generation of oil.

CF4, CI4, CI, and others are also provided ratings by API. Every oils brands need to test its oil and take grade from API. If API doesn’t provide any grades of oil, the brands don’t come with their oil on the market. That’s why API is important for oil companies.

What Is CF4 Oil?

CF4 is a grade-performance oil. CF4 grade and ratings provided by API (American Petroleum Institute). The latest diesel fuel generation is CK, and petrol engine oil is SN. CF4 or CI4 categories are the parameter performance of earlier oil.

On the contrary, CF4 is also the latest generation oil performance grade. Undoubtedly, this oil grade performance is passed by API, and users can easily know the grade of the engine oils via these categories.

Actually, CF-4 means Carbon tetrafluoride, and these API Graded engine oils are best to use in high-speed four-stroke or Turbocharged diesel engine oil.

CF4 Oil
Example of CF-4 Oils

Where Can You Use CF4 Oil?

Typically, this oil is used for the heavy-duty motor engine. You can only use the oil for your vehicle engines according to your manufacturer’s recommendation. The manufacturer of this oil used advanced technology which is ready to protect the engine. For example, your vehicle engine is safe from wear, tear, corrosion, rust, and other harmful elements.

15w40 CF-4 Specification

It is a common oil for most vehicles. If you are a beginner person who wants to consider this oil, you can check out the following specification to know about the oil deeply.

  • This oil meets API CF-4/SJ standards
  • It provides high-performance diesel engine
  • The oil is formulated as a stay-in grade
  • 15w40 CF-4 viscosity index is 139
  • It is specially designed for 4-wheels vehicle

Pros & Cons of CF4 Oil

Every oil has two sides such as pros and cons. CF-4 is similar. I found many advantages and disadvantages of this oil, which are described in the following section.


  • It is a strong oil to protect the engine from wear, tear, rust, and other internal problems
  • Make the engine long-life to run
  • Helps to reduce oil consumption and save oil to use for a long-time
  • Keep the engine clean and avoids bad noise
  • Easy to use and store the oil


  • It may not be commercially beneficial to use small size vehicle

Difference Between CF4 and CI4 Engine Oil

CI4 is a letter and number which identify the service category. When the oil company brings new oil onto the market, they have to pass before it carries and designation.

On the other hand, CF4 is not required to be compatible with the grade of CF or CF4. However, CI-4 is the latest generation of oil grade than CF4. Of course, CF4 is also a good option, but when you think about the latest grade performance, we win the CI4 category.

Note CF4 was first introduced in 1991, and CI4 was first introduced in 2002. Both of these categories are passed by API, and you can easily find all the information to see the letter or number and categories. CF and CI4 are API oil service categories.

You will discover plenty of differences between CF4 and CI4 engine oil. These two engine oils are much popular among the vehicle’s owners. However, I only discuss some core differences between these two oils so that you can compare each other and consider your desired one.

Oxidation Control

The oxidation is a visible difference you find in these oils, such as CF4 and CI4. However, CF4 engine oil comes with lower oxidation control than CI4. The oxidation number of CI4 is four which is higher than CF4 oil.


If you compare these two oils’ dispersancy, you will discover poor dispersancy from CF4 oil. On the other hand, CI4 oil is better and has improved itself on this matter.


From CF4 oil, you will find a density of 0.876 Kg/L. On the contrary, the density of this oil is 0.86 KG/L. So, based on your need, you have to measure the right density.

Comparison Chart of CF4 and CI4 Engine Oil

If you need more to read the detail, you can check out the following comparison chart to hassle-free compare each of the oils.

ParameterCF4 Engine OilCI4 Engine Oil
DefinitionCF4 oil is a high-performance, heavy-duty engine oil which provides more protection for your vehicle engine.CI4 is also an engine oil formulated to sustain engines where exhaust gas recirculation (EGR) is used.
Oxidation ControlLowerHigher
Density0.876 Kg/L0.86 KG/L

FAQs (Frequently Ask Questions)

Q: What does CI4 mean in oil?

Answer: CI4 means the category of oil which comes from the API oil service category. CI4 is the number and letter leveled by API so that users and manufacturers get the correct information. Of course, this grade performance passed by API service.

Q: Is CI 4 oil synthetic?

Answer: CI 4 is a category of API Performance grade. API provides some letters and numbers of the oil so that manufacturers and users can easily know the right information. Generally CI-4 Oil is high Performance mineral diesel engine oil. But currently some companies making CI-4 & CI-4 + Synthetic Oil.

Q: What is API CF 4?

Answer: API means American Petroleum Institute, and they provide oil service categories. However, API ensures that the oil comes with enough performance. After testing, they provide a level with some letters and numbers to categorize the oil or diesel generation. CF 4 is the number and letter, which also means the grade performance of the engine oil.


CF4 is a category and API service. API means American Petroleum Institute, which tests the oils and makes them categories as well as defined with some letters or numbers. After seeing API’s number and letter, users or manufacturers easily understand the oil grade performance. All oil companies need to provide their API oil to pass the oil.


Emon is Lubricants specialist who studied on Petroleum Engineering in UAE. He have more than 10 years experience on different kinds of lubrication including automobile troubleshooting.