Approved, meets, recommended: how do you check an oil approval?

The service book says MB 229.51. On the shelf there are two cans, both with the same number, except that one has the word “approved” next to it and the other “meets the requirements”. The salesman assures you it is one and the same thing, and the second is cheaper into the bargain. Sound familiar? In fact, two different parties stand behind those two lines: behind the first, the carmaker; behind the second, only the oil maker.

What an approval is, and why it is not a mark of quality but a narrow specialisation of the oil, is explained in the article on what oil approvals are. What a genuine approval looks like on the label (“approved”, “Freigabe”), and how it differs from “suitable for” or “exceeds”, is covered in the article on new carmaker approvals. This one is about something else: how to check a line on the can without taking either the label or the salesman at their word. Which, incidentally, is exactly why our oil directory keeps the rows “Manufacturer approvals” and “Meets the requirements of” apart: the same VW 505 00 sits in the first row for some oils, and for many others only in the second.

Who is responsible for each mark

The rule is simple: behind every line on the can there is somebody who answers for it, and a place where you can check it. If there is no such place, all you have is the oil maker’s word.

A carmaker approval: look for the list entry, not the label

An approval exists not on the label but in the carmaker’s list. Anybody can print a label, but an oil gets on to the list only after the tests the carmaker requires.

Mercedes-Benz keeps an open list of approved oils for passenger cars, organised by the numbers of its sheets (229.5, 229.51, 229.52 and so on), and Daimler Truck keeps a separate one for lorries. Look at how the passenger-car list is built: every entry gives the exact trade name of the oil, the company and, as a rule, a single viscosity. In other words, what is approved is not a brand and not a range but a particular oil in a particular viscosity.

ZF publishes its TE-ML gear oil lists openly (aftermarket.zf.com/lubricants): each approved oil has a number of the form ZF000000 there, and each new edition of a list replaces all the earlier ones. What the list numbers and the class letters mean is explained in the article on ZF TE-ML approvals.

Porsche issues overviews of approved oils, giving beside each oil its viscosity, its sales region and the date until which the approval is valid. These are service bulletins, not a page for everybody: Porsche dealers have them.

And if there is no public list? That happens too. Then ask the importer or the oil maker for a copy of the carmaker’s approval letter: it carries the name of the oil, the approval number and a date. Some oil makers post such letters on their own websites. And an authorised service centre for the make can tell you what exactly is specified for your engine.

dexos from GM is a case of its own. It is not an approval in the usual sense but a licence. GM states plainly that a genuine dexos oil carries the dexos badge on the front label and an 11-character licence number (letters and digits) on the back; without those two marks the oil is not licensed and is not recommended for GM cars. So “meets dexos” in small print with no badge does not make it dexos.

API, ILSAC, ACEA and JASO: who stands behind them

API and ILSAC: a licence you can verify

The marks of the American Petroleum Institute (API) — the “doughnut”, the “starburst” and the “shield” — are issued by EOLCS, the engine oil licensing system that has been running since 1993. Only a company that holds a licence has the right to put them on a can. API also buys licensed oils in shops and checks that they match what was claimed; if they do not, the licence can be withdrawn. What the SP, SQ, GF-7A and GF-7B classes themselves mean is explained in the article on API SQ and ILSAC GF-7.

And anybody can check a licence: API keeps an open directory of licensees listing brands, viscosities and classes. If the brand is not in the directory, the badge on the can guarantees nothing.

ACEA: there is no such thing as ACEA approval

This is where many people go wrong. The European Automobile Manufacturers’ Association (ACEA) does not test or approve oils; it only sets the requirements. In its general requirements ACEA states plainly that claims of compliance with its classes are made on the basis of self-certification. That is, the oil maker orders the tests itself and declares the class itself — though under rules: the tests are run in accredited laboratories, the code of ATIEL (the technical association of European lubricant makers) is binding, and only an oil maker that has signed the letter of conformance of EELQMS, the European engine oil quality management system, may declare a class. Registering the claim on the ACEA website is something the association merely recommends.

So “ACEA approved” on a can is at the very least an inaccuracy: there is nobody there to do the approving. An ACEA class is the oil maker’s promise, and it can be trusted exactly as far as you trust the oil maker. What is more, which class suits which engine is, in ACEA’s own words, for the engine maker to decide. How the current classes differ is covered in the article on ACEA 2023.

JASO: registered, not approved

The Japanese JASO classes sit in the middle: the oil maker tests the oil itself and declares the class, but the claim is registered and the oil gets a code. The Japan Lubricating Oil Society (JALOS) keeps open registers of two-stroke oils, motorcycle oils, DH and DL class diesel oils, and oils for petrol car engines. How to read the JASO box on a can is explained in the article on JASO motorcycle oils.

Five traps

1. Region. An approval may not hold everywhere. For BMW petrol engines without a particulate filter, Longlife-04 is permitted only in the countries of the European Union and in Switzerland, Norway and Liechtenstein; outside them such engines need a different approval, as a rule Longlife-01. For diesels and for petrol engines with a particulate filter there is no such restriction. What counts is the country the car is driven in, not the one it was bought in. Inside the EU the restriction will not bother you, but take a petrol BMW without a particulate filter beyond that region, to Ukraine or Türkiye for example, and the Longlife-04 in its “European” service book no longer settles the matter: confirm the oil with the make’s official service centre there.

2. Model year. Porsche’s A40 list of approved oils covers cars of the 1997–2020 model years. Newer Porsches need different approvals, so “Porsche approved” on a can does not mean “for any Porsche”.

3. Validity. An approval does not last for ever. A ZF approval, for example, is valid for 12 months and is renewed only if the oil maker confirms that the formulation has not changed; otherwise it lapses automatically. Lists get rewritten: a new edition replaces all the earlier ones, and an oil that was on the list last year may be gone from it today. A can filled while the approval held can sit on the shelf for a long time — after its entry has already gone from the list.

4. One viscosity instead of a whole range. An oil maker may hold an approval for the 5W-30 and not for the 5W-40 of the same range, while on the website or in advertising all the approvals of the range are sometimes lumped into one list. The carmaker’s list leaves no doubt here: what is approved is a particular name in a particular viscosity.

5. An old data sheet. Technical data sheets (TDS) are dated, and old versions linger online for years. The list of approvals in a three-year-old data sheet is not the same thing as the carmaker’s current list.

How to check your oil: four steps

1. The service book. It gives the exact approval code for your engine, year of manufacture and market, and the viscosity too. Without that there is nothing to check against.

2. The can. Find the same code and the same viscosity, then look at the word beside the code: what it means is clear from the table above.

3. The list. Find the oil in the carmaker’s list (Mercedes-Benz, ZF; for Porsche, at the dealer), in the API directory or in the JASO register, by its exact name and viscosity. If it is not there, or the viscosity there is different, that is no small matter.

4. The document. If there is no open list, ask the importer for a dated copy of the approval letter, or check with an authorised service centre.

I will say it again: what decides is the requirement of your car’s maker, and it is checked not by the line on the label but by the entry in the list of whoever issued that approval. And if the can says only “meets the requirements” while the salesman swears it is the same thing, ask whose signature is under those requirements. The choice is yours, but for a car under warranty the answer is, as a rule, obvious.