Reading manufacturer approvals and specifications
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A container of motor oil carries up to four kinds of information, and only one of them is binding for your vehicle: the manufacturer approval called for in the owner's manual. The SAE grade describes only the viscosity, API and ACEA describe a performance level, and a vehicle manufacturer's approval says that this exact product has passed that manufacturer's own engine tests. Read in that order, and you will find the right oil in a minute.
SAE: viscosity, not quality
5W-30 is an SAE viscosity grade. The number before the W stands for cold behaviour: the smaller it is, the more freely the oil flows on a cold start and the sooner oil pressure builds at all the lubrication points. The number after it describes the thickness at operating temperature. The grade says nothing about how well an oil cleans, how long it lasts or whether it is suitable for a particulate filter. Two 5W-30 oils can be intended for completely different engines.
API: the American performance level
The API classes consist of two letters. S stands for petrol engines, C for diesel engines, mostly in the commercial vehicle sector. The second letter runs on alphabetically; the newer the class, the higher the requirements: SN became SP, and in the commercial vehicle sector classes such as CK-4 apply. Newer classes generally cover the older ones, which is why in Europe API usually appears as a supplementary detail. Oils in the current petrol engine class are under API SP.
ACEA: the European standard
The ACEA sequences are what European manufacturers refer to. They fall into three groups:
- A/B for petrol and diesel engines without special requirements for exhaust aftertreatment, such as A3/B4 for engines that call for an oil with high shear stability.
- C for vehicles with a catalytic converter and particulate filter. These classes limit ash, phosphorus and sulphur and additionally differ in HTHS viscosity; the most common is ACEA C3.
- E for commercial vehicle diesel engines with their own, much longer intervals.
The ACEA class is a minimum requirement, not a substitute for an approval. If your vehicle calls for an approval, the matching ACEA class alone is not enough.
Approved or merely meets: the important difference
Containers carry two wordings that look very similar. A genuine approval names the vehicle manufacturer and its test number; the product is listed with that manufacturer and has been through its engine tests. Wordings such as ‘meets the requirements of’ or ‘recommended for’, on the other hand, are statements by the oil maker about its own product, with no outside testing. Technically such an oil may well be suitable; in a warranty case, though, the approval is what counts, and at lease returns and fleet audits it is checked.
The approvals that count in Germany
- VW: 502 00 and 505 00 for fixed intervals, 504 00 and 507 00 for the Longlife service, 508 00 and 509 00 for the especially thin oils of newer engines. These numbers are not interchangeable.
- Mercedes-Benz: the sheet numbers of the MB approvals, such as 229.51 or 229.52 for vehicles with a particulate filter and the older 229.3 and 229.5 for engines without.
- BMW: Longlife-04 as the most widespread requirement, alongside Longlife-01 for older vehicles and Longlife-17 FE+ for newer ones.
- Other manufacturers with numbers of their own: Opel and GM with dexos, Ford with the WSS specifications, PSA with the B71 numbers, Fiat with 9.55535 and its appended code, Renault with the RN numbers, Porsche with the A and C approvals.
How to read a container in the right order
- Look up in the owner's manual or the service schedule which approval and which viscosity are prescribed for your engine. Two engine variants of the same model series can have different requirements.
- Check on the back of the container that exactly this approval is listed, and listed as an approval rather than a recommendation.
- Only then compare the viscosity grade, and after that pack size, brand and price.
- If in doubt, consult the oil's technical data sheet. It lists the approvals in full, with the date of each approval.
The shortcut via the vehicle
If you would rather skip the looking-up, go the other way round: choose make, model and engine in the oil finder, and the list shows only oils approved for that vehicle. The full range with all the filters by approval and viscosity is in the Motor oil category. What sets the individual oil types apart is explained in the article Mineral, semi-synthetic, fully synthetic.
Frequently asked questions
Is the right viscosity enough?
No. The SAE grade only describes the flow behaviour. Whether an oil belongs in your engine is decided by the approval, and two oils of the same viscosity grade can be intended for very different engines.
What is the difference between an approval and the wording ‘meets the requirements’?
An approval has been tested and listed by the vehicle manufacturer. ‘Meets the requirements’ is the oil maker's own statement without that testing, and does not carry the same weight in a warranty case.
Can I replace VW 502 00 with VW 504 00?
Not automatically. The numbers stand for different concepts and additive packages. What counts is the number named in the owner's manual, not the higher number.
Where do I find the complete list of approvals for an oil?
In the manufacturer's technical data sheet. The container often names only the most important approvals; the data sheet lists them all, with the date of each approval.
Do older approvals still apply when newer ones exist?
What applies to your vehicle is what the maintenance schedule says. Newer approvals supersede older ones only if the vehicle manufacturer expressly says so.
Which oil suits your car?
The oil finder narrows the catalogue down to the oils approved for your model - choose make, model and engine, and you are done.
Open the oil finder