The next heavy duty performance category is here, superseding API CJ-4, which was first introduced in 2006.

First license of the new oils was 1st December 2016.

This category upgrade through the American Petroleum Institute (API) has global ramifications as many oil marketers wish to offer the same product globally; a product that meets a more comprehensive spectrum of specifications.

For the first time ever, the category is split into two:

API CK-4: backward compatible and supersedes API CJ-4 (HTHS viscosity 3.5 cP or higher)
API FA-4: for modern engines, offering greater fuel economy benefits (HTHS viscosity 2.9 - 3.2 cP)

These oils predominantly affect:

Large diesel engines, including heavy duty and medium duty over-the-road vehicles
Off-highway vehicles including construction and agricultural equipment

API CK-4 offers performance way beyond that of API CJ-4, driven by new technology and verified stringent testing.

These have the same viscosity grades as those oils we know today (typically SAE 15W-40, 10W-30, 5W-40 and 5W-30 grades).

The API CK-4 Service Symbol Donut looks the same as the current API CJ-4 Donut.
A new API Service Symbol Donut features a shaded section to differentiate API FA-4 diesel oils from API CK-4 oils.

API FA-4 oils have to pass the same set of tests as API CK-4, and are for modern engines recommended by the OEM for further improved fuel economy.

API FA-4 lubricants will typically be SAE 10W-30 and 5W-30 viscosity grades.

The new tests are oxidation and aeration, while shear stability limits are raised, providing greater protection for all engines. API FA-4 requires passing the same tests as API CK-4 with the addition of a High Temperature High Shear (HTHS) limit for lower viscosity oils.

Universal oils – those carrying API C (Commercial Vehicles) as well as API S (Gasoline Passenger Car) are based on new formulation styles with a lower phosphorus limit, protecting emission reduction systems in passenger cars.

The benefits of lubricants also having specific OEM approvals means oils have been tested to conform to their specific requirement for the specific engine. These requirements can differ from OEM to OEM, but can cover areas such as tests for:

  • Daimler/Detroit Diesel’s specification involves a test to evaluate a lubricant’s ability to prevent heavy duty scuffing or adhesive wear, unique destructive wear patterns.
  • Cummins’ new specifications covering API CK-4 as well as API FA-4 oil for use in their engines.
  • Volvo/Mack’s new specifications include an oxidation test incorporating more stringent limits than API.
  • Such higher performance lubricants with additional OEM performance claims gives greater reassurance of greater protection, durability and performance for the vehicle throughout its life.

For OEMs, these oils help achieve greater fuel economy and provide additional engine protection–helping OEMs keep up with regulatory pressures and in developing new, more efficient and lower emission engines.

For oil marketers, these oils offer further opportunity and incentive to differentiate. However, the further fragmentation of oil types within API CK-4, API FA-4 and universal oils make it necessary for oil marketers to act quickly in moving away from API CJ-4 oils.

For end users, including fleet managers and those purchasing API CK-4 and FA-4 oils, these oils offer even greater durability and fuel economy opportunities when running existing and new vehicles. Knowing the recommended oils for a given truck is now essential, given the split category.

Lubrizol has been developing API CK-4 and FA-4 technology and formulations, already with tens of millions of miles accumulated in both on and off-road engines (over 50 million and growing).

This ensures real world durability and performance, giving confidence of performance additives and polymer solutions within the lubricant from the first day the licensing came into force.

Lubrizol Corporate Headquarters - Wickliffe, Ohio

For more detailed information on the latest API categories click here:

For more information contact your Lubrizol Account Manager or visit our website:

Copyright 2016 The Lubrizol Corporation. All rights reserved.

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