Why we don't publish a lubricant equivalence chart
A chart that lines up products from different manufacturers by viscosity grade and base number reads like evidence and is not. Why we do not print one, and how a grade is matched against the specification and the approval instead.
Quick answers
Is there an equivalent chart for marine lubricants?
We do not publish one. A chart lines up products from different manufacturers by viscosity grade and base number, but what an oil is approved for can only be stated by its manufacturer or by the engine builder's own documents. We match a grade against the specification and the approval evidence instead, and state the result in writing.
Does the same viscosity grade mean two lubricants are interchangeable?
No. HLP 46 and the zinc-free HLP ZF 46 have identical viscosity at 40 °C and 100 °C, but different additive chemistry and a different flash point. Two NLGI 2 greases can be chemically incompatible. A matching number describes one property, not the product.
How do you find a replacement for another brand's lubricant?
Send the data sheet of the product in service with the engine or equipment details. The match is made on the specification class, the viscosity grade, the base number where the fuel decides it, the approval the equipment requires and compatibility, and we state in writing which SINOVA Marine or Tomoil grade meets the same specification.
"Marine lubricants equivalent chart" is a search people make often enough for Google to suggest it: a table with another brand's product in one column and a replacement in the next. We do not publish one. The reason is not reluctance to be compared. It is that a chart of that kind makes a claim it cannot support.
What an equivalence chart actually claims
A cross-reference chart is almost always built from two or three numbers on a data sheet: the viscosity grade and, for engine oils, the base number. Products that share those numbers end up in the same row, and the row then reads as a statement that one can replace the other.
The numbers are real, but each one describes a single property. What separates a good match from a bad one sits in the parts of the formulation the chart does not show.
Why a matching number is not a matching product
Three examples, all from the published data and the articles in this library:
- HLP 46 and HLP ZF 46 have identical viscosity: 46.00 mm²/s at 40 °C and 6.650 mm²/s at 100 °C. One uses zinc anti-wear chemistry, the other is ashless, and the flash point differs, 230 °C against 216 °C. On a chart they would share a row. In a circuit with bronze components or servo valves they are not the same choice.
- Every grease in our range is NLGI 2, and they are not all mutually compatible. Grease WR2 is thickened with calcium, the general purpose greases with lithium. Matched on consistency they look interchangeable; mixed in a bearing they can soften or harden and leave it without oil.
- A cylinder oil's base number is a chemical budget, not a quality ranking. Formulations built for distillate and ultra-low sulphur service are balanced differently from those built for residual fuel, which is why the number alone does not say where an oil belongs.
What a chart cannot carry: the approval
For engine oils the decisive document is usually an approval: a validated listing, a No Objection Letter or an OEM approval certificate. Each one names an exact product and grade. An NOL for a BN 70 cylinder oil does not extend to the BN 100 in the same product family, and it does not extend to another manufacturer's oil that happens to share the number.
A chart that sets a product without that document beside one that holds it implies the approval travels across the row. It does not, and that is the claim we are not willing to print.
A statement that two oils are equivalent can only come from the manufacturer of the oil or from the engine builder's own documents. Anything else is a comparison of data sheets and should be presented as one.
How we match a grade instead
The match is made against the specification, one variable at a time, and the result is stated in writing.
- Specification class: the DIN 51524 letters for a hydraulic oil, or the class the equipment maker's manual names.
- Viscosity grade: ISO VG or SAE, and the viscosity at the temperature the oil actually runs at, not only at the 40 °C reference.
- Base number, for engine oils: set against the sulphur of the fuel being burned and the feed rate.
- Approval: whether the engine or equipment requires a validated or approved oil, and which document covers the grade.
- Compatibility: the thickener for a grease; for a change of base fluid, the seals and the flushing procedure.
What to send
- The data sheet of the product currently in service.
- Engine or equipment make and model, and the specification or approval its manual calls for.
- Operating conditions: the oil temperature in service and, for engine oils, the fuel sulphur on the current bunker delivery note.
- Whether you are topping up or changing the whole charge.
With those, we state in writing which SINOVA Marine or Tomoil grade meets the same specification, with the approval evidence attached where a document exists.
Related
Need this confirmed for your engine?
Send us the engine make and model and the fuel you are burning. We will confirm the grade in writing, with the approval evidence attached.
Ask the technical desk