Written By: Corey Foy

Engine Oil Specifications


Knowing what lubricant you need really comes down to the specifications. Ensure that you are sourcing engine oil that meets the most up to date specs. When you do this they are often (not always) backwards compatible with previous generations.


Diesel Engine Oil Specifications

The newest specs for diesel engine oil are the API CK-4 and FA-4. These were launched in December 2016. API CK-4 replaced the API CJ-4 spec and is backwards compatible. CK-4 brings improvements in wear protection, sheer stability, and oxidation control.

API FA-4 provides similar improvements. The difference is FA-4 are for use in on-highway diesel engines. API uses a donut to help you differentiate between CK-4 and FA-4.


Diesel API Donut


Gasoline Engine Oil Specifications

The newest specs for gas engine oil are GF-6A and GF-6B. These were launched in May of 2020. These new specs are backwards compatible with older GF-5 and API SN oils.

But, keep in mind:

  • GF-6A is for viscosity as low as 0W20
  • GF-6B is for 0W16 oils
  • API SP is backwards compatible for API SN oils

These new specs include performance improvements with increased protection against low-speed pre-ignition (LSPI), timing and chain wear, and better fuel economy. API uses the logos below.

Gasoline Engine Oil Spec



As you can see, making sure you are using the right specs lets you gain all the benefits from the new required testing. This means direct improvements in both protection and performance.

If you ever have any questions about your oil specifications please call or text our Technical Specialist - Corey Foy at 780.238.6598.