How to Choose Oil for a Heavy-Duty Truck

Start with the engine make, model, year, and series. Then confirm API category, ACEA sequence, OEM approval, SAE viscosity, aftertreatment, fuel, and service condition. The brand or 15W-40 grade alone does not define the right oil.

What information is needed?

• engine and serial number;
• year and emissions standard;
• required API and ACEA categories;
• Volvo VDS, Mack EOS, Cummins CES, Detroit Diesel, MB, MAN, or another approval;
• viscosity and ambient temperature;
• DPF, EGR, and SCR;
• fuel sulfur;
• load, route, idle time, and hours;
• interval, consumption, and analysis;
• capacity and package.

CK-4 or FA-4?

API CK-4 is a broad category for current and many earlier four-stroke diesel engines. FA-4 is a lower-HTHS category for selected engines and is not backward compatible with CK-4.¹

Do not use FA-4 without authorization from the engine manufacturer.

15W-40, 10W-30, 5W-40, or 5W-30?

Select the grade according to the manual and temperature. A 5W grade can improve cold behavior; an XW-30 grade can support efficiency when the engine permits it. Florida heat does not authorize changing the required viscosity.

What changes with DPF and SCR?

The oil must carry the category and approval compatible with the aftertreatment. The wrong product can increase ash or affect durability. Do not choose by “low SAPS” alone.

Which active options does Inforca carry?

Inforca publishes several CK-4 options:²

Product	Grade	Selected coverage
MANNOL TS-14 UHPD, MN7114	15W-40	CK-4; ACEA E11/E7; Mack, Renault, and Volvo approvals; other specifications in the data sheet
MANNOL TS-17 UHPD, MN7117	5W-30	CK-4 and OEM/ACEA coverage listed in the data sheet
MANNOL TS-16 UHPD	5W-40	CK-4 in the public list; confirm TDS
MANNOL TS-18	15W-40	CK-4; confirm the current matrix
PureGuard PG206	15W-40	CK-4/SN synthetic blend according to the supplied sheet

The table provides an initial screen. Verify approval, API license, package, and availability.

How should two proposals be compared?

Compare line by line: product/SKU, API, ACEA, approvals, viscosity, TDS, license, package, traceability, availability, and delivered terms. A lower price does not offset a missing approval.

Can the interval be extended?

Only through the manufacturer’s program and analysis trends. Keep the initial interval when changing products.

Frequently asked questions

Is the best oil always synthetic?

No. The best fit satisfies the requirements and produces the measured operating result.

Does CK-4 replace CJ-4?

API states that CK-4 exceeds CJ-4, but confirm the engine, fuel, and interval.¹

Can one oil cover the entire fleet?

Only if a verified matrix covers every engine.

Does higher viscosity provide more protection?

Not necessarily. Use the design range.

Does oil color indicate quality?

No. Verify the label, license, and data sheet.

Send the engine and approval

Send Inforca the engine/series, API, ACEA, OEM approval, viscosity, aftertreatment, duty cycle, monthly volume, and package. The team can compare documented options.

Sources

Footnotes

1. American Petroleum Institute, Oil Categories, accessed September 10, 2026. ↩ ↩²

2. Inforca International, Products, accessed September 10, 2026. ↩