OEM, OE and Aftermarket: What does it all mean?!

We operate in a complex field; the automotive industry evolves daily with increasing technological advancements it’s more important than ever to ensure the parts that you’re fitting are 100% correct for the car on your ramp.

What does OEM mean? And where can you find the OEM part numbers for a specific vehicle?

As a garage owner, mechanic or vehicle owner, you need to know that the parts you’re ordering are correct. The OEM number helps you to ensure that the parts you purchase are the right ones, but other acronyms are banded around, so how do you know what to look for?

What does OEM stand for?

Original Equipment Manufacturer, so the OEM number refers to the part number by the used by the vehicle manufacturer. The manufacturer does not produce individual components themselves, instead they outsource this production to specialist manufacturers.

What does OE stand for?

OE stands for Original Equipment. This describes the parts that are produced for the vehicle manufacturers that are still sold independently, or a part that is produced to the standard of the original. For example, TRW may produce the brakes pads for BMW, but if they’re supplied by BMW, the box is marked with BMWs branding, if they’re supplied by an independent parts supplier, they would be supplied without any BMW branding despite the part being technically identical.

What does IAM stand for?

IAM refers to Independent After Market. They’re parts that aren’t produced by the original manufacturer, in some cases these can be better or worse quality than the original parts. In some cases, aftermarket components can address common failure points and even make improvements. But in other cases, cheaper ill-fitting components can result in premature failure and more issues than they’re worth.

What does MPN stand for?

MPN stands for Manufacturer Part Number, this number is the part number that the vehicle manufacturer uses to identify its parts. They often follow a logical structure to help parts departments quickly identify components for mechanics and customers.

Where can you find the OEM numbers?

There are several ways to find your OEM number.

  • Often the OEM or OE number is marked on the part. You usually do have to dismantle the parts for this but if you were planning on getting them remanufactured its no additional work.

  • There are online part databases where you can search for suitable parts and the corresponding OEM numbers by inputting the VIN number of the car. Once you have your OEM number, you can easily find the corresponding part on the ACTRONICS website.


ACTRONICS has linked the entire remanufacturing range to OEM numbers, this means that you can easily find the correct part. You can do this by entering the part number at in the top search bar and then you can submit your repair order form.

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