Az495
Questions and answers
Short, self-contained answers, from the basics to practical cases. Answers expand when you tap them, but all of them are in the page text.
The basics
What is an OEM part number?
The part's number in the carmaker's catalog. It identifies the part unambiguously and is used to find aftermarket equivalents.
How does an OEM part differ from an aftermarket one?
An OEM part is supplied under the carmaker's brand. An aftermarket part is made by another manufacturer; it may match in size and specifications, but quality depends on the specific manufacturer.
What is a cross-reference number?
A number that links an OEM part to aftermarket equivalents. Aftermarket manufacturers publish cross-reference tables.
Where do I find the VIN?
On the registration certificate, the vehicle passport (PTS/EPTS) and a plate in the car. A VIN has 17 characters.
Practical cases
My car has no VIN, only a frame number
This is the case for some cars built for the Japanese domestic market. Many catalogs can search by frame number (chassis number); if not, you will need the model, engine and production date.
What is a facelift and why does it matter?
A mid-cycle update to a model. After a facelift, headlights, bumpers, wiring and other parts may change, so the model year does not always determine the right part.
The number on the old part doesn't match the catalog
The part may have been replaced before, or the manufacturer has issued a new version with a different number (a supersession). Ask a dealer which number is current.
Can I return a part that doesn't fit?
That depends on the seller and the law in your country. Don't fit a part until you are sure it is compatible, and keep the packaging and receipt.
Related sections
- Reference sections
Map of the reference: part numbers, selection by VIN, OEM vs aftermarket, buying.
- Practical guides
Step-by-step part selection by VIN and part number, plus the catalog of upcoming publications.
- Reference
Terms and part number formats — the essentials, with examples.
Sources
- ISO 3779 — VIN structure
- Catalogs of carmakers and aftermarket manufacturers
Information is current as of the preparation date. Manufacturer catalogs and part fitment change — check the official catalog or a dealer before buying.