The American Petroleum Institute (API) has released a series of tips for service providers for accommodating them and training technicians about the application of the trucking industry’s newest heavy-duty diesel engine oils, API CK-4 and FA-4.
API says CK-4 oils succeeded CJ-4 engine oils and are backward compatible diesel oils. Backward compatible means CK-4 may be used where CJ-4, CI-4 with CI-4 PLUS, CI-4, CH-4, and earlier service categories are recommended. API FA-4, on the other hand, is a new arrival intended for engines built beginning with the 2017 model year. There are currently 430 CK-4 oils and 65 FA-4 oils licensed by API and more are expected, API says.
CK-4 provides improved shear stability, oxidation resistance, and aeration control over CJ-4 in the familiar SAE 15W-40 and 10W-30 viscosity grades. API says FA-4 provides similar protection to CK-4 oils, but in lower viscosity grades to meet the needs of next-generation diesel engines being built for the 2017 model year and onwards. FA-4 oils meet the same performance measures as CK-4 but API says they also help increase fuel economy in engines designed for the lower viscosity FA-4 grades.
API says key improvements to the new oils include the following:
- Shear Stability – Shear stability is the resistance of oil molecules to shearing or breaking down under extreme stress inside the engine. Shear causes oil to decrease to a lower viscosity, and excessive viscosity loss could affect how well the oil can protect the engine. CK-4 and FA-4 oils with have improved shear stability compared to CJ-4 oils.
- Oxidation Stability – Oil oxidation is one of the main reasons for oil breakdown and it occurs more readily under higher engine operating temperatures. With many newer engines running hotter, CK-4 and FA-4 standards deliver improved oxidation stability versus CJ-4 oils.
- Aeration – Aeration is the entrainment of air bubbles in the oil, which can limit the ability for oil to cool and protect the engine. Newer engines with higher operating temperatures and pressures can increase the amount of air trapped in oil. As oil is more regularly used as a hydraulic fluid for valve-train actuation, this task can be compromised by aerated oil. CK-4 and FA-4 oils provide greater protection against aeration.
- Fuel Economy – You may have heard of the term High Temperature High Shear (HTHS) as the new oils were being developed. CK-4 oils are being called “High HTHS” engine oils because their viscosities are the same as those found in CJ-4 oils. In contrast, FA-4 oils are being called “Low HTHS” oils because their viscosities are lower. These Low HTHS oils have been developed to provide engine manufacturers with a tool that will help them meet more stringent fuel economy and greenhouse gas emissions requirements.
With some new diesel engines requiring FA-4 oils, API says customers, shops and technicians need to know how to manage CJ-4, CK-4, and FA-4 oils in their facilities. API recommends service providers create a transition plan for the shop; there may be a need for increased storage and the clear identification of the lubricants will reduce confusion.
API says first estimate the volumes of each oil a shop will require. Always check with the truck manufacturer to see whether they require FA-4 or CK-4 oil and the viscosity grade needed.
Be sure to mark tanks, storage, tools, etc. in advance of the first delivery of product to avoid co-mingling different products and misapplication. Assess a shop’s need for both oils and check on the availability from your supplier. Also ask about specific viscosity grades since some are changing. Identify a clear date to incorporate the new oils into the shop and clearly communicate that information to staff, API adds.
Here are six things API says service shops can do to ensure the new oils are being installed and dispersed properly.
- Engine Requirements – FA-4 oils may not be recommended for all new engines, so be sure to check with engine manufacturers about which engines are supposed to use FA-4 oil.
- Bulk Tanks – Replacing CJ-4 with CK-4 should be a simple transition because CK-4 is backward compatible and an improvement over CJ-4. You can still carry CJ-4 oils in drums if you want to keep some on hand.
- Inventory – Monitor volumes of API CJ-4 lubricants vs. API CK-4 & FA-4 to ensure proper supply.
- Identification – Clearly mark all bulk or packaged oil as appropriate for API CJ-4, CK-4 & FA-4 oil
- Dispensing Oil – All dispensing equipment should be properly labeled with product name and viscosity grade to prevent misapplication.
- Education – Technicians should be made aware of the changes to oil categories and requirements for each.
To help technicians and consumers differentiate between the two new oils, API also has developed a special Service Symbol Donut. The new FA-4 donut features a shaded section that sets it apart from the traditional Donut being used with API CK-4.
For more information from API regarding the new oils, please go to www.dieseloilmatters.com.
