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PC-11 Q & A

We answer some of your pressing questions.


An ongoing Question and Answer series created to help prepare you for the transition to PC-11.

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When will the next engine oil grade be introduced onto the market and will there be a similar 10 year gap between PC-11 and its successor?

In general, there is desire from all stakeholders to make sure that the categories that we introduce have lasting value so that the significant investments made can be recouped. API CK-4 and API FA-4 are demanding and robust and offer flexibility to service both newer engines and older engines. From that standpoint, we see them having value for many years to come. However, we’re also aware that engine and vehicle designs will continue to evolve in response to tightening emission regulation and new end-user demands. Engine OEMs are already developing new tests that could become the basis for next generation performance specifications. We remain committed to making sure that engine oil standards keep pace with the needs of the marketplace.

Are you already working on PC-12?

Formally, no, but it isn’t too early to start thinking about the next set of requirements. New oil specs over the past 20+ years were introduced primarily due to changes in emissions regulations (first pollutants, now greenhouse gases) and there are already proposed standards that will continue to tighten over the next ten years. These tougher standards will undoubtedly require changes to engine designs that will introduce new demands on lubrication. More practically, some of the engines that are used to evaluate oils against current standards are quite outdated and long term availability of service parts is questionable. At some point, it will be prudent to part ways with historic requirements (e.g. high soot control) that just don’t seem relevant to modern engines, but that are retained for purpose of “backwards compatibility”. For these reasons, it is safe to say that.

What will the panel’s role be after PC-11 has been introduced?

We’ll continue to make sure that OEM requirements are met by assuring that the tests remain available, that replacement parts are in abundant supply, and confirming that the category is meeting the needs as originally defined. Meanwhile, there are already new tests under development. Daimler is developing an engine test, the DD13 Scuffing Test, which evaluates adhesive power cylinder wear control performance. This test was not included as a requirement for API CK-4 or API FA-4, but is proposed for use in their future OEM specifications and is being developed as an ASTM standardized test under the jurisdiction of HDEOCP.

What is the ASTM Heavy-Duty Classification Panel’s (HDEOCP) role now that the PC-11 specifications have been approved?

The HDEOCP is an evergreen committee within ASTM, so it is not just focused on the new PC-11 specs, but that is clearly our focus at the moment. Right now, we’re working to formally standardize the two new engine tests that are included in the category – the Volvo T-13 test and the Caterpillar Oil Aeration Test. Both of these test procedures are in the final stages of approval to be adopted as official ASTM standard test methods. For each test, Surveillance Panels are established, with representatives from the OEMs that sponsor the test, test laboratories that run the tests, oil and additive companies that test their products against the requirements, and ASTM staff that provides independent oversight to monitor the tests and the labs that run them. Having clear and detailed documented procedures is pivotal in maintaining test integrity, assuring that tests that are run in different labs or at different points in time continue to give a true and accurate assessment of the oil’s performance.

What is the biggest of worry, concern and confusion in the marketing surrounding PC-11?

According to a recent CCJ survey, almost 48% of respondents are slightly to very concerned about the implementation of PC-11. Respondents’ top concerns included: the fear that lower viscosity oils will increase engine wear ; possibility of needing both API CK-4 and FA-4 oils; determining the right oil for their fleet; and not being able to use the new formula in older engines and what will happen if it is used in older engines.

Are CK-4 and CJ-4 Compatible?

Yes, they are fully compatible, and there should be no concern if the two are mixed. However, full performance benefits of API CK-4 oils will only be realized when the engine is full transitioned from API CJ-4 to CK-4.

What is High-Temperature High Shear (HTHS) Viscosity and why is it important?

You may not know it, but there are actually four viscosity measurements that are made to define and engine oil’s viscosity grade. The most familiar measurement is kinematic viscosity (KV) which is most commonly run at 100oC and is included in most standard used oil analysis reports. HTHS viscosity is also important, as it is run at a higher temperature (150oC) and also under stressed conditions that are more relevant to the oil’s performance in hot regions of the engine, including bearings and in the overhead. There has been a tremendous amount of testing that has shown that oils with lower HTHS viscosity can improve fuel economy. In fact, the HTHS viscosity is the primary difference between oils that will be classified as API CK-4 or API FA-4. API CK-4 oils will have HTHS viscosity of 3.5 cP or higher, while API FA-4 oils will have HTHS between 2.9 cP and 3.2 cP.

This is why it will be critically important to pay attention to not only the oil’s SAE viscosity grade, but also the API performance level (CK-4 or FA-4) to identify the product that is right for you

Will OEMs be issuing their own specifications aligned with these new categories?

Yes. It has become very common for engine makers to issue their own specifications which incorporate requirements from the industry standard along with additional OEM-specific requirements to help customers spec oils that are appropriate for use in their engines. In some cases, this involves using the same performance tests, but with more stringent limits. In other cases, new OEM-specific tests are introduced and required alongside the standard tests. This is particularly true for OEM-specific material compatibility tests and other bench tests that the engine builder has determined to be particularly relevant to their needs. We expect that OEMs will be issuing specifications tied to API CK-4 and/or API FA-4 in the very near future.

Where will PC-11 be available upon its release?

The American Petroleum Institute (API) will begin allowing products meeting the new specs (API CK-4 and API FA-4) to claim these specs “in the donut” starting on December 1, 2016. At that point, you should expect to see the new products available in all of the same distribution channels that supply API CJ-4 products today. Be sure to talk to your oil supplier about how you can get ready for these changes.

I’m concerned that I’m going to have to stock two oils now. Is that the case?

Definitely not! While it is true that these new specifications were motivated by the needs of emerging engines that meet the latest greenhouse-gas emission standards for on-highway trucks, the specs were structured in a way to limit the complexity for the end-user. API FA-4 oils will be recommended for some model year 2017 engines and may even come “factory filled” from the OEM with FA-4. As is the case today, it will remain important for you to evaluate the OEM recommendations for performance spec and viscosity grade for all of the engines in your fleet and to select the product that comprehensively meets your needs. In many cases, that will be an API CK-4 product that offers the greatest backward compatibility and will be allowable for use in engines new and old!

What are the advantages to me as a consumer?

These new specifications include new performance requirements that make API CK-4 and API FA-4 significant upgrades to API CJ-4. Most notably, oils that meet the new standards will have SIGNIFICANTLY improved oxidative stability. This means that they will be formulated to provide protection against premature breakdown, even when the oil is exposed to the very high operating temperatures that are common in today’s hard working engines. In fact, one of the new oil performance tests required by the new specs runs the oil at 130oC (266oF!) for 360 hours in an engine running at full power! You can be assured that oils meeting the new standards are up to the task of protecting your engine, even under the harshest of conditions.

Will the additive packages change in the new oils?

Engine oils meeting API CJ-4 will definitely need to be reformulated to meet the demanding new requirements of API CK-4 or API FA-4. In many cases, this requires changes to the core additive system to optimize for wear protection while also bringing significantly improved oxidation stability and improved protection against viscosity loss due to shear. However, these new categories retain the same “chemical box” that was introduced for API CJ-4. So the limits on the amount of sulfated ash, sulfur, and phosphorus (sometimes referred to as “SAPS”) haven’t changed, meaning that these new improvements come without a compromise to protection of your emission control system. If you subscribe to a used oil analysis program, it will be important to establish new “baselines” to reflect the additive package of the new products – just like you do any time you change to a new oil brand.

When pulling heavy loads will this oil affect the performance?

Modern engines, as well as the specifications for the engine oils that lubricate them, are developed to address ever expanding customer needs, including the need to operate under sever duty service which can place significant stress on the oil and demand that it stand up to high temperatures when operating conditions dictate. The new API CK-4 and FA-4 specifications build off today’s standards, requiring strong wear protection, deposit control, with even more stringent requirements for protection at high operating temperatures. From that standpoint, you can be assured that the new oils will be even more robust to severe duty operation. As always, consult your owner’s manual for oil recommendations consistent with your engine make/model and service severity.

How will these new oils perform in cold weather?

Although the new low viscosity products have been developed to improve engine and vehicle fuel economy, they also perform better at low temperature when compared to conventional SAE 15W-40 products. 10W and 5W heavy-duty engine oils must be pumpable and allow the engine to start at temperatures 5oC to 10oC colder than a 15W-40. Better low temperature fluidity means that engine oil will travel faster upon start up to the lubricated components inside the engine contributing to better wear control and engine durability.

In addition to fuel-efficiency, how are these new oils protecting the engine from oxidation?

This is a great question, because it highlights a common misconception about the new engine oil categories. While the new specifications were certainly motivated by the need to introduce new more efficient engines and vehicles, there will also be a significant performance upgrade with the new oils in addition to the new lower viscosity grades. When engine manufacturers requested this new category back in 2011, they were clear that the new oils needed to be significantly more resistant to oxidation. That is to say they need to stand up to higher temperatures, for longer periods of time without breaking down. So, as these new products have been developed, particular attention has been given to making sure that the right combination of high quality base oils and advanced additive technology – tenants that are at the heart of Chevron Delo® with Isosyn technology – are brought together to answer the needs of the most stringent heavy-duty motor oil specification ever developed.

What tradeoffs have been made to achieve better fuel economy and reduced emissions with PC-11 oils?

Oil formulation is certainly a balancing act. In fact, the API CK-4 and FA-4 specifications each require that 9 engine tests, each with unique performance requirements, and several bench tests be passed to demonstrate robustness to wear, deposit formation, and premature oil breakdown. In addition, engine oils must flow at low temperatures while still providing adequate protection when they are passing through the hottest parts of the engine. Of course, the needs for emission control system protection put constraints on the types of components (and how much of these components) that can be used in the finished product. None of this would be possible without access to the highest quality lubricant base oils and advanced additive technologies working together.

How has Chevron been testing these oils under real world conditions?

It takes thousands of hours of engine dynamometer testing to qualify new products against these demanding test standards. But at Chevron, we understand that true proof of performance can only be demonstrated by exposing our products to real life customer demands – on the road, on the farm, in the heat of summer and the dead of winter. Chevron and our partners have been testing new PC-11 engine oils in a variety of equipment, both on-road and off-road, to further demonstrate the performance benefits of these new products so that you can be assured they’ll stand up to the rigorous demands of your fleet’s operations.

Who conducts these tests?

In most cases, product qualification to demonstrate performance against the PC-11 specification requirements takes place at independent third-party testing laboratories. These facilities adhere to strict quality standards and are overseen by test monitoring organizations to assure that tests are run in accordance with industry standards.

Field test programs are more commonly run in cooperation with customers who allow all or part of their fleet to use prototype test lubricants. In these tests, used oil analysis is conducted during the evaluation and selected engines are disassembled and inspected at the end of the test to further validate the performance of the oil. Our goal is to confirm that our products are delivering the deposit protection and wear control our customers count on from Delo.

What kind of engine damage will occur if the wrong oil type is used? Will one-time use damage the engine or will it happen over time?

Because API CK-4 will be backward compatible to previous licensable API categories, there will be no adverse effect from using these oils in older equipment. As always, it is important to confirm the viscosity grade(s) that the OEM recommends for a particular make, model and vintage. In some cases, there are restrictions on using lower viscosity grades (like SAE 10W-30) in some older engines.

The same is generally true for API FA-4 oils. We expect that OEMs will recommend it in a much more limited set of engines and applications, especially in the near term. In particular, we do not anticipate they will be recommended in off-highway applications. We expect OEMs to publish more specific guidance on the limitations or restrictions associated with these lower viscosity oils later in 2016, before they hit the market.

The impact of improper oil selection depends on a number of circumstances, but it is unlikely that a one-time use would cause immediate damage or failure. More commonly, use of oil with a lower viscosity than the engine was designed to use would cause a low oil pressure light, which in some cases triggers additional safeguards, including engine derate, to limit potential engine damage. Prolonged use could lead to premature wear or engine failure. It is important to consult your owner’s manual for specific guidance related to the proper viscosity grade and performance specification that applies to your specific engine and vehicle.

What are the fuel efficiency targets for the different sizes and weights of on-road vehicles?

The greenhouse gas and fuel economy standards that were jointly issued by the U.S. Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration (NHTSA) in 2011 are quite complex, but in essence they mandate reduction of carbon dioxide (CO2) emissions and fuel consumption in medium and heavy duty vehicles. The exact emissions and fuel economy standards vary by model year and vehicle class. In general, the target is up to 20% improvement compared to baseline 2010 model year vehicles. In fact, even tougher standards have already been proposed that will force even better fuel economy over the next 10 years.

What are the expected improvements in carbon emission reduction?

The greenhouse gas and fuel economy standards that were jointly issued by the U.S. Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration (NHTSA) in 2011 are quite complex, but in essence they mandate reduction of carbon dioxide (CO2) emissions and fuel consumption in medium and heavy duty vehicles. The exact emissions and fuel economy standards vary by model year and vehicle class. In general, the target is up to 20% improvement compared to baseline 2010 model year vehicles. In fact, even tougher standards have already been proposed that will force even better fuel economy over the next 10 years.

Are PC-11 oils expected to be more expensive to the customers?

There are a number of factors that can influence the price of oil, so it is difficult to generalize. One thing that we understand well is that most of our customers are running a business. Our objective is to understand how their fluid selection best integrates into their operation and how it can positively affect their bottom line. This includes selecting a product that meets the technical requirements of all of the hardware they utilize, as well as considering the potential advantages of longer maintenance interval and improved fuel efficiency.

Are the PC-11 specifications approved?

Yes! In December, the ASTM International's Automotive Lubricants Subcommittee approved the new Proposed Category 11 (API CK-4 and API FA-4) specifications for the next generation of heavy duty diesel engine oils, which will be licensed on December 1, 2016.

How will you determine which PC-11 oil is right for your fleet?

As is the case today, selecting the right engine oil product for your fleet starts with an evaluation of the types of engines (make, model, vintage) that make up the fleet. Your Chevron representative will then be in a position to recommend the products that carry the industry and OEM specification credentials along with the viscosity grade options that meet the engine maker’s requirements. This will be increasingly important with PC-11, since there will be even more choices and new OEM requirements and restrictions.

How has oxidation resistance been improved in PC-11 oils?

When the PC-11 category was first proposed by OEMs back in 2011, it was clear that engine makers were looking for new motor oils with significantly improved protection against oil breakdown at elevated temperature (oxidation). This has forced oil formulators to utilize new additives in combination with more stable base oils to deliver the improved performance. As a lubricant marketer with an additive technology supplier and base oil refiner “under one roof”, Chevron Lubricants is uniquely poised to meet these new and emerging requirements for higher performing heavy duty motor oils.

Will the new PC-11 HDMO offer the same protection?

PC-11 products will have new cutting edge technology developed for additional wear and oxidation resistance allowing for improved engine protection and reliability versus API CJ-4 oils. Furthermore, PC-11 formulations will have the same limits on sulfated ash, sulfur, and phosphorus content which have proven to help maintain and maximize- the life of emission control systems (Like Diesel Particulate Filters – DPF).

What is the difference between CK-4 and FA-4?

The primary difference in the two categories of PC-11 heavy duty oil is with backward compatibility. API CK-4 oils will support virtually all high-speed four stroke cycle diesel engines – including older engines that were using CJ-4, as well as new engines that are currently being developed. Use of API FA-4 oils will be OEM dependent and may not be suitable for use in older diesel engines. This category will focus on the next generation of diesel engines that are currently in development to deliver greater fuel efficiency. Other differences include:

  • PC-11A (Licenses as API CK-4)
    • Viscosity grades include both SAExW-40 and xW -30 engine oils with >3.5 cP HT/HS viscosity
    • Higher level of wear and oxidation protection versus API CJ-4 oils
    • Improved shear stability
  • PC-11B (Licenses as API FA-4)
    • Improved fuel economy performance versus API CJ-4 oils
    • Applies only to SAE 10W-30 and SAE 5W-30 viscosity grades that have are between HT/HS viscosity in the range of 2.9 to 3.2 cP
    • Developed to deliver excellent engine parts protection even with thinner oil films
When will the new PC-11 oils hit store shelves?

API will allow licensing of these two new standards beginning on December 1st, 2016. We expect API CK-4 products to show up on retail and wholesale shelves by December 2016.

What are the benefits of these PC-11 oils?

The principle goals of the new engine oil categories are to increase fuel efficiency and to help reduce CO2 emissions. However there are REAL performance upgrades that are being introduced as well. These new oils will deliver greater oxidation stability to meet the needs of hotter running engines, benefiting not only the new engines, but also existing engines that are running at very heavy duty cycles. The off-highway segment can really gain benefit from the use of these new CK-4 oils, which will deliver significantly improved oxidation stability.

How is component life and/or performance affected with the use of PC-11 formulated oil on new engines?

PC-11 oils will be formulated to be more resistant to oxidation – this means that they can stand up to elevated temperature for longer periods of time without “breaking down.” This is something that engine makers identified as a priority because of the greater demands that new engines are placing on the oil, as well as the desire for longer oil change intervals. The use of oils not meeting these new requirements may compromise the end users’ ability to achieve maximum OEM-published oil drain intervals. Using the new oils also ensures that the operator is taking advantage of the latest advancements in wear protection and viscosity control. Obviously, picking the right viscosity grade is important – not only considering operating climate, but also potential for improved fuel economy.

Which PC-11 oil should be used for off-highway vehicles?

Since API CK-4 can be used to replace all API CJ-4 (previous category of oil) use scenarios. We expect API FA-4 to be recommended in a much more limited set of engines/applications, especially in the near term. In particular, we do not anticipate API FA-4 being recommended in off-highway applications. We expect OEMs to publish more specific guidance as to the limitations (or restrictions) associated with these lower viscosity oils in 2016, before they hit the market.

What role does low viscosity PC-11 oils play in regards to fuel economy?

While high film thickness oils have been used for a number of years, lower viscosity has become a bigger focus given the need for enhanced fuel economy. The fuel economy improvement that can be expected from using lower viscosity oils depends on the engine type and duty cycle, and with the oil that is selected. Compared to conventional API CJ-4 SAE 15W-40 oils, studies have shown that fuel economy improvements of 1.5% or more can be achieved when oils like those that will be licensed as API FA-4 are used.

Why is PC-11 offered in 10W-30 and HTHS 10W-30?

Lower viscosity oils can provide better fuel efficiency. While some will be hesitant to shift to lower viscosity oils, those looking to take greater advantage of fuel economy may want to consider the low high-temperature high shear (HTHS) viscosity 10W-30 API FA-4 oil, which is developed for optimized fuel economy. Since these oils will only be recommended for certain new on-highway engines, it is important to first consult with your engine OEM for guidance on the appropriate specification and viscosity grade that is compatible with your hardware.

What does the new PC-11 specifications mean for off-highway applications?

While off-highway market is not directly affected by the same regulations that are driving on-highway engine design changes, PC-11 has shown to have benefits that are applicable to the off-highway market. Oil aeration is a common problem with off-highway equipment, when air bubbles proliferate into the hydraulic or circulating system this can lead to foaming, cavitation and an increased oxidation rate. PC-11 oils are developed to provide improved resistance to oil aeration, in addition to enhancing shear stability and oxidation protection.

Is this just for new trucks with diesel engines?

While PC-11 has been developed to target performance improvements in newer engines, many of these improvements are important to all engines, new and old alike. In particular, the API CK-4 category will be backwards compatible, incorporating performance requirements from the previous category (API CJ-4), while introducing new requirements for improved oxidation stability, aeration control and shear stability. API CK-4 oils will be offered in a variety of viscosity grades including the SAE 15W-40 and SAE 10W-30 grades that are most commonly used and recommended today.

Isn’t the new oil the same as the older oil, just thinner?

No, the new PC-11 products are formulated with new generation additive technology to provide improvements in performance for diesel engine operators. There are two categories:

  • API CK-4 which will be offered in the same viscosity grades as current API CJ-4 oils and remain backward compatible with older engines.
  • API FA-4 licensed oils are also formulated with next generation additive technology but with lower viscosity to provide both engine protection and improved fuel economy versus API CJ-4 engine oils – these products are NOT backward compatible and are developed for new model diesel engines.
Isn’t PC-11 just for on-highway markets? Is this relevant for the off-highway market?

PC-11 will offer improvements to engine oils that are important for diesel engines of all types, even off-highway! With improved oxidation stability, wear performance and shear stability, PC-11 oils will deliver additional benefits to customers around engine durability, oil drain interval extension and a wider range of products formulated for a wide range of off-road applications.

Why do we need a new heavy duty engine oil category?

In 2010, the U.S. Environmental Protection Agency and National Highway Traffic Safety Administration (NHTSA) announced regulations designed to reduce greenhouse gas (GHG) emissions and mandate fuel economy improvements for medium and heavy-duty engines and vehicles. The new regulations would be phased in between 2014 to 2017, imposing different fuel-efficiency targets based on the size and weight of vehicle/equipment types. Diesel engine design is undergoing a period of significant change to meet the new requirements. The Engine Manufacturers Association (EMA) in turn made a request for the American Petroleum Institute (API) to develop a new commercial engine oil performance category to address engine oil requirements of these new engines.

There are two outgrowths of these new regulations that are driving the formulation of the new oils. For one, the new engine designs run hotter, which puts an increased demand on oil formulas to withstand higher heat environments and actually be able to run longer when exposed to higher temperature. Secondly, it is recognized that engine oil can play a direct role in improving fuel economy, through the use of lower viscosity grades. The EMA request included a proposal to introduce a subcategory with lower viscosity than allowed by previous performance categories.

Who is determining what these oils will look like?

There are committees with representation from API, EMA, and the American Chemistry Council (ACC) that are overseeing the development of the new PC-11 engine oil standards. Fleet personnel and owner operators can be confident that these oils will provide appropriate engine protection and operating reliability, while supporting incremental fuel economy performance over current API CJ-4 SAE 10W-30 and SAE 5W-30 oils.

Why do we need two categories of heavy duty oils?

A new generation of oil is required to protect the new generation of engine designs. In the development of the PC-11 category, it was determined that two subcategories would be developed. One category will be referred to as API CK-4 which represents a direct, backwards compatible, upgrade to the current API CJ-4, which will not only be suitable for new engines, but also will be suitable for use in older engines. The second category will be licensed as API FA-4 and will introduce new lower viscosity products developed for newer diesel engines and specifically formulated for optimized fuel economy. Engine OEMs also may allow these FA-4 oils in some older engines as well. As always, it is important to consult with your engine supplier for specific guidance on the selection of allowable viscosity grades for your specific hardware.