OEM vs aftermarket packaging: identify car parts by the box and the part number

What a genuine carmaker box carries

The carmaker’s trademark, the carmaker’s part number and, for some brands, a security feature. A Mercedes-Benz dealer explains that GenuineParts themselves are marked with the protected Mercedes-Benz trademarks and, where there is room, the part number, and that the packaging uses a uniform design and labeling. On primeline items, the safety parts and regular service parts such as oil filters, brake pads and air filters, a hologram seals the box and is destroyed when the box is opened. Insist that it is intact.

Volkswagen India prints a QR code and a scratch-off hologram on its parts boxes. Under the hologram sits a 10-digit code that you enter on the Volkswagen Group’s authentication site.

Each carmaker uses its own features, and the Volkswagen example comes from its Indian site. Find out what your brand’s box should show where you buy before you judge one.

OE-supplier boxes: the supplier’s logo on the carmaker’s part

An OES part comes from the company that supplied the factory, packed in that company’s box. Our post on OEM vs genuine parts sets out the terms.

In the EU, the supplier’s logo on the part is protected. Under the motor vehicle block exemption, an agreement that stops a component supplier putting its trade mark or logo, clearly visible, on the parts it supplies is a hardcore restriction. The Commission’s guidelines explain why: repairers and consumers should be able to identify which parts from other suppliers match a given vehicle. So a part bought from the dealer can still carry the supplier’s logo, and the same part in the supplier’s own box carries the supplier’s brand and article number. Neither of those makes it a fake.

Aftermarket boxes and cross-reference numbers

Brembo publishes a guide to the label on its aftermarket brake disc boxes. The top carries the Brembo logo, country of origin, ECE R-90 approval where applicable and a barcode. The middle carries the product number, in a format like 08.1395.40, with flags such as HC for high carbon or “screw kit”. Lower down come the quantity, front or rear axle, tightening torque, minimum thickness, the main car applications, a hologram and an anti-counterfeiting QR code.

Notice what the list leaves out: the carmaker’s part number. The box names the cars it fits. The link from the carmaker’s number to the aftermarket number sits in catalogs and databases. TecAlliance says its TecDoc OE Parts Data is checked against the carmakers’ official electronic parts catalogs and used to match OE numbers to aftermarket equivalents.

Identify OEM vs aftermarket parts by the part number format

Carmaker numbers follow house formats, and supplier article numbers follow the supplier’s own. If you can’t tell which kind of number is printed on a label, paste it into the free OEM number lookup. A number that matches no carmaker format is usually a supplier or aftermarket reference.

Don’t read the barcode as a country of origin. The first three digits of an EAN-13 barcode are the GS1 prefix, which usually identifies the GS1 member organization the company joined and doesn’t necessarily say where the product was made.

A tidy label proves little, since fakes copy labels. Our checks on spotting counterfeit parts cover print quality and security codes.

Confirm the number by VIN

Enter the VIN in the carmaker’s catalog, open the diagram and read the number beside the part. That is the genuine number for your build, with any supersession applied. A genuine box should carry that number, or a later one the catalog lists as its replacement. Old stock can carry an earlier number from the same chain, which is fine as long as the catalog links the two.

If the box number matches neither the catalog nor anything in its supersession chain, stop. Either the part belongs to another build, or the box isn’t what it claims to be.

For an OES or aftermarket box, take the catalog number to the supplier’s own catalog and check that its article number is listed against it. On VINsearch the Mercedes-Benz catalog and the rest open in the browser, from $5 for a Day Pass.