OE: Original Equipment.
OEM: Original Equipment Manufacturer.
OE parts are the parts of the vehicle that are built at the factory, i.e. all the original parts from which the car was originally built. After the car leaves the factory, all other parts are not OE parts.
OEM on the one hand means that the manufacturer is the original manufacturer of the part, and the OEM part is produced for a specific make and model and has been approved for use in that brand of vehicles. These certifications mean the approval of the manufacturer’s production equipment and technicians to follow the OEM’s approved procedures. By using OEM parts, the structural integrity of the vehicle can be maintained, as well as the resale value of the vehicle itself, and its performance and use effects are basically the same as when it left the factory.
The vehicle manufacturers do not manufacture many products themselves but rather they contract their Original Equipment Manufacturers (OEM’s) to do so.
In some cases OEM produts are even better quality than what is currently available in Genuine, because over time genuine contracts end, then parts will be stamped with the OEM’s brand name such as Bosch, Hella, not the vehicle manufacturer’s logo.
To give a clearer and more intuitive example, BMW Motor Company entrusts a certain auto parts to factory A for processing and production, and affixes the BMW trademark for sale. Such products are called OE products. But if BMW does not buy out the ownership of the product, then Factory A can produce the exact same product and sell it without the BMW label, which is an OEM product. Usually the same product OE will be more expensive than OEM.
The difference between OE and OEM in the automotive aftermarket