The newest generation of engine oil is now in market and owners of heavy-duty vehicles stand ready to reap the benefits. For years, your partners at Phillips 66 have been preparing for this category upgrade with millions of miles of lab and on-road testing. The results? Unprecedented. All of our engineered formulas in the API CK-4 and FA-4 categories exceed standard industry requirements and have proven to maximize fuel economy and wear protection, and minimize emissions.
CK-4 and FA-4 heavy-duty engine oil maximizes fuel economy and wear protection so you can maximize savings and cost efficiency. See how much you can save with our Fuel Savings Calculator.
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Every single test conducted with Phillips 66 products vastly surpassed the API requirements. In addition to reducing emission levels and improving fuel economy, our formulas also provided significant engine protection by decreasing wear, corrosion, and the formation of sludge and grit deposits.
1. What do fleets need to know going forward about using CK-4 oils?
a. Simply put, CK-4 oils are the next natural extension of their CJ-4 predecessors with more robust performance in certain categories as demonstrated through a few upgraded API test parameters and a few new OEM tests. CK-4 products will be completely back-serviceable to cover all of the same diesel applications that CJ-4 did, just with higher performance standards.
There is an additional change that the new specification brings with regard to “universal” engine oils (those which claim both “C” categories for diesel and “S” categories for gasoline engines). In order for a diesel engine oil to claim an “S” category, it must now meet all of the gasoline category’s criteria including the limit on phosphorous levels. Phosphorous has long demonstrated proven protective qualities versus ashless chemistries in diesel engines but has also been known to shorten the life of automotive catalyst systems in gasoline engines. This means that a diesel engine oil must be below 0.08% phosphorous to claim an “S” category approval (the CJ-4 specification allows up to 0.12% phosphorous). The loophole which used to allow higher phosphorous levels from diesel engine oils when used in gasoline engines will be effectively closed. In practical terms, this will create a clear line in the sand between diesel-only formulations (“high phosphorous”) and universal oils (“low phosphorous”).
2. What properties make FA-4 better suited for 2017 engines?
a. Over the past 20 years or so, each heavy duty engine oil category upgrade has focused on reducing emissions. As oils began to reach the limits of their contribution toward lower emissions, engine manufacturers began to design exhaust treatment systems to further reduce NOx and particulates (particulate filters, EGR, SCR and other technologies). Now that diesel emissions have been reduced to historic lows on a per truck basis, the focus has shifted to fuel economy. 2017 engines and the new FA-4 oils are being designed to work together to provide better fuel economy. The major factor distinguishing FA-4 oils from their CK-4 counterparts is that they have lower High Temperature High Shear (or “HTHS”) values. HTHS is an additional measure of viscosity representing internal fluid friction – the lower this value, the better the fuel economy versus an oil of the same kinematic viscosity (expressed a centistokes or “cSt”) with a higher HTHS. In other words, there will be SAE 10W-30 oils in both the CK-4 and FA-4 categories with their main differentiator being their HTHS values. Where CJ-4 and CK-4 require a minimum HTHS of 3.5 cP (centipoise), FA-4 oils will feature HTHS values in the range of 2.9 – 3.2cP.
3. Explain why CK-4 is a high HTHS formula and FA-4 is a lower HTHS. Exactly what does that mean?
a. It is important to note that there are multiple measures of viscosity – the most common being kinematic viscosity (reported as centistokes [“cSt”] and representing a fluid’s resistance to gravitational flow). Absolute viscosity is another measure which represents frictional drag within the lubricant itself. The lower this value, the less fluid friction. High Temperature/High Shear testing measures the absolute viscosity of a lubricant in a test designed to emulate the area between an engine’s crankshaft and the connecting rod journal bearings in a warmed up engine. The test is performed at 150°C and its value is reported in centipoise (designated as “cP”). There has been a great deal of testing that shows oils with a lower HTHS can provide improved fuel economy versus oils of the same viscosity with a higher HTHS. As we look at these next generation oils then, the reason for the split categories was to clearly identify products with these different HTHS values. CK-4 will require a minimum HTHS of 3.5 cP while FA-4 oils will be in the range of 2.9 – 3.2 cP.
4. Explain the viscosities for the new oils. Is all CK-4 oil 10W-30 viscosity? Is FA-4 5W-30 or 10W-30 or both?
a. CK-4 products will include all of the legacy viscosity grades including the most popular, 15W-40. FA-4 product viscosities will likely be limited to lower viscosity grades such as 5W-30 and 10W-30. It is possible to have the same viscosity grade offered in both performance categories. For instance, a 10W-30 viscosity grade product would exist in both CK-4 and FA-4 formulations with the difference being a lower HTHS value for the FA-4 lubricants. API has introduced a new donut for the FA-4 specification to clearly identify through wording and color that the category is different. See the example below:
5. Will CJ-4 still be around after the introduction of the PC-11 brands? If so, for how long? Is there still a reason to use it?
a. Some companies may choose to maintain select CJ-4 products for a while after the introduction of CK-4. However, given that CK-4 will be back-serviceable for all applications previously calling for CJ-4, Phillips 66 intends to upgrade its current CJ-4 lubricants to CK-4 upon 1st licensing (December 1, 2016).
6. It seems like FA-4 oils are designed for the on-highway haul trucks. What about vocational trucks such as dumps and cement mixers?
a. Given that these are severe duty applications and the owners are less concerned with fuel economy, is there any reason to use an FA-4 oil in vocational trucks? FA-4 oils may provide fuel economy benefits for all vocations and types of service. However, during the early stages of availability the jury is out as to how many end users will convert. The testing requirements of FA-4 are the same as CK-4, so durability and protection attributes will be robust in both categories. As always, equipment operators need to check with the equipment OEM for recommended viscosity grade and service category information.
7. Are there any concerns about engine performance if these oils are accidentally mixed in an engine?
a. Topping off an engine with CK-4 / FA-4 when the other was called for would not result in anything catastrophic as they both will have passed the same category performance levels. One must always be mindful of maintaining the correct viscosity, though, for proper engine protection.
8. What are the properties that make these two oils effective for their individual applications?
a. CK-4 oils are broadly applicable for on-highway and off-road applications, just like CJ-4 today, while FA-4 oils are specifically designed to accentuate the fuel economy characteristics of 2017 (and beyond) engine designs. Back-serviceability of the FA-4 oils will be determined by the engine manufacturers. However, it is worth noting that both FA-4 and CK-4 oils will be subject to the same durability testing. As always, fleet operators will need to evaluate their performance and maintenance goals as well as the OEM’s recommendations in order to determine the right mix of products for their equipment.