PC-12 Readiness Advances, but OEM Guidance and Commercial Value Remain Open Questions

Nearly six in ten respondents to JobbersWorld’s PC-12 Readiness Survey say their organizations are fully or mostly prepared for the transition. Yet supplier schedules remain uneven, OEM guidance is still evolving, and expectations for meaningful FB-4 demand are limited. The findings suggest that technical preparations are advancing faster than the commercial and operational decisions needed to bring the new oils to market—and that recovering the costs of conversion may prove harder than the technical changeover itself.

The analysis draws on 72 survey responses received October 1–26, 2026, and follow-up discussions with lubricant distributors and blenders. Together, they provide an early assessment of the challenges surrounding first licensing of API CL-4 and FB-4 on January 1, 2027.

Who Responded

Distributors account for 49 of the 72 responses, or 68.1%. Another 15 respondents are blenders/manufacturers, six are marketers/brand owners, and two are retailers. No respondents selected end user/fleet operator.

These are the views of businesses supplying lubricants, not fleets buying them. Participation was voluntary, and the results do not provide a statistically representative picture of the lubricant industry.

JobbersWorld followed up with distributors and blenders to ask how they expect the transition to affect their businesses. Their comments, reported without attribution, add context to the survey findings.

What PC-12 Changes—and What It Does Not

PC-12 introduces CL-4 as the successor to CK-4 and FB-4 as the successor to FA-4. First licensing begins January 1, 2027. API describes CL-4 as meeting or exceeding CK-4, CJ-4, CI-4 and CH-4 performance requirements. [1]

FB-4 covers lower high-temperature/high-shear, or HTHS, viscosity oils for select engines designed to meet 2027 on-highway emissions standards. It includes xW-30 and xW-20 grades. FB-4 is not a general substitute for CK-4 or earlier C-category oils. Its use in engines currently running FA-4 also requires the appropriate viscosity grade and OEM approval; an FB-4 xW-20 should not be assumed suitable wherever an FA-4 xW-30 is used. [1] [11]

CL-4 keeps CK-4’s higher HTHS viscosity requirements. PC-12 does not move every heavy-duty engine to a thinner oil. HTHS measures viscosity under demanding operating conditions; it does not identify an oil as conventional, synthetic blend or full synthetic.

FA-4 and CK-4 oils can both carry an SAE 10W-30 designation, but they differ in HTHS viscosity. The size of that difference depends on the products compared; approved applications must be checked against the engine manufacturer’s recommendations. [1]

Both new categories lower the maximum phosphorus content from 0.12% for CK-4 and FA-4 to 0.08%, or 800 ppm. The sulfated-ash maximum falls from 1.0% to 0.9%, and sulfur from 0.4% to 0.3%. These are category limits; the actual amounts in individual products can be lower. [1]

The lower phosphorus limit restricts the use of phosphorus-containing antiwear additives such as zinc dialkyldithiophosphate, or ZDDP. ZDDP has a long record as an antiwear additive. Reducing the phosphorus allowance—and, in some FB-4 applications, moving to lower HTHS viscosity—makes evidence of wear protection particularly important. Those changes do not, by themselves, demonstrate poorer protection; performance depends on the complete formulation and its validation. CL-4 and FB-4 oils must meet specified wear and scuffing requirements, including the Cummins ISB and ISM tests and the Detroit Diesel DD13 scuffing test. [1] [5]

Supplier Timing Shapes Readiness and the Product Changeover

Most respondents have heard from their primary supplier about the transition. Of the 72, 57 (79.2%) report a formulated product or an expected transition date; the other 15 say plans are not firm yet. The reported schedules vary considerably, as the table below shows.

The first two groups total 40 respondents, or 55.6%. The remaining 32 report either a transition after January 1 or plans that are not firm. Suppliers are therefore expected to change over at different times. A product formulated to meet PC-12 requirements is not necessarily API-licensed or available throughout a supplier’s distribution network.

On organizational preparedness, 17 respondents say they are fully prepared and 24 mostly prepared. Together, they account for 56.9%. Another 15 have some preparation underway, 11 report little preparation, and five are not sure.

Respondents with firmer supplier plans also report greater readiness.

Of the 16 respondents reporting products already formulated, 15 are fully or mostly prepared. Of the 15 whose supplier plans are not firm, 13 report little preparation or uncertainty. The survey does not prove that supplier communication caused the difference. It does underscore the need to know which replacement products suppliers will offer and when they will be available.

Blenders/manufacturers report the highest readiness: 13 of 15 are fully or mostly prepared, compared with 27 of 49 distributors. None of the six marketers/brand owners reports being fully or mostly prepared. These comparisons describe the respondents, but the small groups—particularly brand owners and retailers—do not support broad conclusions about those business segments.

Of the 71 respondents answering the product-change question, 26 expect moderate changes and 24 minor changes. Combined, those answers account for 70.4%. Ten expect little or no change, six say it is too early to tell, and five expect significant changes. Three of those five are marketers/brand owners.

In the interviews, a recurring expectation is that new formulations will replace existing products as stocks are sold, with little immediate change in customers’ normal buying patterns.

Interview feedback included plans to start bottling new formulations around mid-November 2026, while keeping existing specification labels until first licensing. The transition raises practical questions about which production lots contain the new oils, whether product codes will change and when new labels will appear. Early reformulation does not change the first licensing date of January 1, 2027.

Product changes and inventory cutovers are closely tied to engine-specific OEM approvals. Uncertainty over those approvals could complicate the timing of the conversion, particularly where customers may still require existing CK-4 products.

OEM Guidance Tops the Unresolved Issues

OEM guidance and approvals are the most frequently selected unresolved issue, with 25 of 71 answers, or 35.2%. Survey comments also raised Group III base-oil availability, which matters where the new formulations depend on those stocks.

Asked what would help future transitions, 24 of 69 respondents, or 34.8%, selected better coordination among OEMs, API and industry. Greater OEM flexibility in approvals and transition requirements followed with 15 selections, or 21.7%.

OEM guidance does not always mean a single required oil. Detroit’s experience illustrates the distinction between a preferred oil and an approved alternative. Detroit endorsed FA-4 at the category’s 2016 introduction and subsequently adopted it as factory fill. Its published guidance recommends DFS 93K223 FA-4 oils for fuel economy in the listed EPA10, GHG14, GHG17 and Gen 5 applications, while also permitting DFS 93K222 CK-4 oils. [8] [9] [10]

Fleets using the covered engines may therefore have an OEM-approved alternative to the preferred lower-HTHS oil. That is not a blanket statement that CK-4 and FA-4 are interchangeable; the particular engine’s recommendations still govern. [8]

Off-road OEM guidance: an unresolved inventory risk

The off-road concern is more specific: some OEMs may not endorse CL-4 because of questions about wear protection with its lower-phosphorus chemistry. Interviewees worry that suppliers could convert to CL-4 before learning that certain engines still require higher-phosphorus CK-4 formulations. Blenders and distributors would then need to retain or reintroduce those products, adding inventory and the risk of selecting the wrong oil.

Six survey respondents selected off-road applications as their biggest unresolved issue. Six also selected better guidance outside the primary specification targets as the most helpful improvement for future transitions.

The concern predates these interviews. In December 2023, Infineum reported that some off-road OEMs had durability concerns about the proposed lower chemical limits. They preferred to remain on CK-4 and requested continued availability of an enhanced CK-4 option with at least 0.10% phosphorus and the new Volvo T-13 and DD13 performance targets. The report did not name the OEMs. [2]

Subsequent Lubes’n’Greases coverage also discussed off-road concerns and possible continued demand for CK-4. These accounts describe discussions during category development, not evidence that Caterpillar, John Deere, Komatsu or another equipment manufacturer has rejected CL-4. [3]

The tension is not new. On-road and off-road heavy-duty engine oil requirements have been diverging since CJ-4, introduced for 2007 on-highway engines, became the first API C-category to limit sulfated ash, phosphorus and sulfur. Each subsequent category has been shaped largely by on-highway emissions requirements, while off-road engines face different duty cycles and durability expectations. The lower phosphorus limit in CL-4 has caused particular concern in the agriculture, mining and construction sectors. Until off-road OEMs make their intentions clear, that concern is likely to continue.

API permits qualifying CL-4 formulations to also be licensed as CK-4, CJ-4, CI-4 (including CI-4 PLUS) and CH-4. This could allow suppliers to serve multiple API categories with a single product. However, a CL-4 formulation licensed this way remains subject to the new category’s 800 ppm phosphorus limit, and API backward compatibility does not guarantee acceptance by every OEM. [1]

API’s heavy-duty categories establish maximum phosphorus limits, not minimums. Consequently, CK-4 itself does not require higher phosphorus content. The distinction becomes important if an off-road OEM specifies a phosphorus minimum above 800 ppm or imposes other requirements that a CL-4 formulation cannot satisfy. Under those circumstances, suppliers may need to maintain higher-phosphorus CK-4 formulations. Until OEM recommendations are clear, distributors serving off-road and mixed-fleet customers face uncertainty over which products they will need to carry.

What the Published Tests Show

Wear-protection evidence will be an important consideration as off-road OEMs evaluate CL-4. Suppliers have published test results supporting the new formulations. Infineum’s October 2026 brochure reports more than 20 million miles of field testing, on- and off-road validation at 800 ppm phosphorus, and comparisons with CK-4 technology and competing products. [4]

Afton reports strong Cummins ISM and ISB wear performance from formulations below the new phosphorus limit, based on laboratory testing and extended field trials. Afton says its results show that protection can be maintained through the overall formulation, rather than by relying on phosphorus concentration alone. [5]

For customers considering a change, the practical questions are whether the specific oil carries the required OEM approvals and what performance benefits have been demonstrated in comparable equipment and operating conditions.

More useful comparisons would identify the oils, engines, duty cycles, drain intervals and measured wear results. Meeting API requirements shows that an oil meets the category’s standards. An OEM recommendation identifies where it can be used. Comparative field testing helps show whether it delivers benefits in a customer’s particular operation.

Recovering Conversion Costs

Interviewees indicated that customers may resist broad price increases for PC-12, even though suppliers and distributors must spend time and money preparing for the change.

As noted in a JobbersWorld PRO article published September 11, 2026, reformulation, qualification, packaging changes and inventory management carry costs. Recovering those costs through higher prices may be difficult, according to the interviews. Sellers will need to show customers what benefits the new oil offers beyond a different specification on the label.

The interviews point to limited early demand driven by OEM requirements. One participant described anticipated demand as a “trickle” in the first quarter of 2027 and expected it to remain soft through the rest of the year. A recurring view is that customers will see PC-12 as another specification change, not a reason to buy more oil or pay substantially more. One interviewee cited the price increases customers had already absorbed during 2026 as a reason they might resist another increase tied to PC-12. These are expectations, not firm market predictions.

Interviewees identified longer diesel particulate filter, or DPF, life from lower lubricant-derived ash as a possible benefit, but questioned whether the improvement would be large enough to matter in customers’ operations. Product-specific field data would help establish its size and economic value.

One interviewee expects fewer regeneration events. That claim needs evidence from the particular product. Regeneration burns soot; it does not remove accumulated lubricant-derived ash. Lower ash accumulation can affect filter capacity and regeneration behavior, but fewer regenerations, longer intervals between ash cleanings and longer filter life are different benefits. [6]

Chevron’s Delo 600 ADF shows why the comparison matters. It is a CK-4 oil with 0.4% sulfated ash, well below PC-12’s 0.9% maximum. Results from that product cannot be assumed for every CL-4 or FB-4 formulation. [1] [7]

Whether customers will accept a price premium may depend on evidence that a particular oil delivers measurable benefits in their equipment, such as fewer maintenance events or longer OEM-approved drain intervals. The interviews suggest price resistance, not that customers will refuse to pay more when those benefits can be demonstrated.

Longer drains could reduce maintenance events and downtime where OEM recommendations and operating conditions support them. They could also reduce lubricant consumption. If customers change oil less often, distributors may sell fewer gallons. Sellers will need to consider whether higher margins on the oil or revenue from related services can offset the lower volume.

Limited Expectations for FB-4

Only two of 72 respondents, or 2.8%, expect meaningful FB-4 demand or use.

The interviews tell a similar story, citing limited FA-4 uptake and fleet reluctance to adopt lower-viscosity heavy-duty engine oils, or HDEOs. One participant described expected FB-4 volumes as “minuscule,” while allowing that it could command a premium.

These expectations do not predict FB-4’s eventual market share. A distributor’s need to stock it will depend on the engines its customers operate and the oils their OEMs recommend. Low overall demand would not make FB-4 optional for a customer whose engine requires it.

Detroit’s acceptance of CK-4 provides an approved alternative in the covered engines; it does not tell us how widely fleets choose that alternative. Low FA-4 volumes alone cannot establish substitution rates. [8]

A further concern raised in interview feedback is reluctance to adopt xW-20 oils. These grades are an important addition within FB-4, not a requirement for every PC-12 application. [1]

What It Means for Lubricant Sellers

The survey and interviews point to practical decisions that sellers need to resolve: which replacement products will be available, which engines can use them and which existing oils must remain in inventory. Clear supplier schedules and engine-specific recommendations are essential to managing the conversion.

Distributors and marketers should confirm replacement products, supply dates, product codes and label changes with their suppliers. Those serving construction, agriculture, mining or mixed fleets need to check OEM requirements before dropping existing oils from inventory. FB-4 stocks should be based on the engines customers actually operate, not an assumption of broad early demand.

The next tests are practical: do suppliers meet their schedules, do OEMs publish clear recommendations, and do field results support the benefits sellers promote?

For lubricant sellers, a successful PC-12 transition will depend not simply on having compliant products available, but on managing the changeover without disrupting customers, confirming engine-specific approvals and demonstrating benefits sufficient to justify the costs of conversion.

About the Survey

This analysis is based on 72 voluntary survey responses received October 1–26, 2026. Percentages use the number answering each question: 72 for business activity, supplier plans, preparedness and FB-4 expectations; 71 for product changes and unresolved issues; and 69 for future-transition priorities. Results are unweighted and describe the respondents, not a statistically representative estimate of the lubricant industry or fleet demand. Small subgroup comparisons should not be generalized to whole business segments. Follow-up discussions with distributors and blenders add context and are reported without attribution.