Where do third-party spare part vendors get the information which parts fit which models?

Question

I work in the Automotive industry in a small company that supplies parts to different vehicle manufacturers. We sometimes have a hard time finding out which models our parts go into, the manufacturers being kind of secretive about this.

Dedicated third-party spare part vendors however seem to know quite well which models the respective parts fit into (see picture below).

Now obviously there are official part catalogs with exploded views, some of which can be found online for free. But the most credible source would be the manufacturers themselves, and their publications are priced correspondingly.

Do third-party vendors buy those official publications? How is such data normally obtained (if not officially bought)?

Answer 1

The parts manufacturer, in the example Hella, will produce a range of parts which goes into a range of cars. When the cars are new, the manufacturer of the parts will have agreements in place to supply certain products to certain vehicle manufacturers. For example, the original Volkswagen timing belt on my Mk6 Golf was marked up with Continental logos and the tensioner with a Gates stamp. I've bought fuel filters over the counter from Volkswagen that have come in VW branded packaging but with MANN manufacturers markings on them.

Many parts will not be sold exclusively to one manufacturer. The good old Pierburg 2E2 carburettor is a good example as these were used on many Vauxhall and Volkswagen cars.

The original manufacturer of the parts will know which cars their parts are going into and publish product catalogues accordingly. They'll also have their own unique parts numbering system and they will maintain "cross-part" compatibility charts.

A good example of this is the Gates product catalogue which is freely available online here; gatesautocat.com The Mintex Brake Book is another example.

It's in the suppliers best interest to ensure that their re-sellers are able to access this information freely because in this way, they are more likely to sell a higher volume of their product. If any parts reselling operation were setting up, they'd likely demand up-to-date product cross reference guides as part of the re-seller agreement.

So, in short, the best place to find this information is the parts manufacturers (not the vehicle manufacturers).

Answer 2

If you supply to different car manufacturers then you have agreements with them and they would provide parts listings and detail appropriate.

This will obviously depend on several things such as the contract and data protection for both sides...

The car manufacturers do not hand out detailed information to just anyone for good reasons and I worked at one manufacturer where the VIN could be expanded to give the original build information of the car - if you have the codes and lookup tables necessary...