My friend works in a MB dealership as a SA and we had a discussion on OEM parts recently.

He is against after-market parts. He said although a part is made from the same manufacturer, they may not make the part in the same specs as given by MB. So, it is a hit-and-miss and we will never know what we are getting. The OEM parts are cheaper but maybe they will have to be changed more frequently. Considering the labor cost, I may not be saving much.

Recently I bought a Mann pollen filter from an online store and when I compared it to the old MB filter, I found it to be much lighter and a lot less sturdy. I also ordered a Mann oil filter and now I am not sure if I want to use it.

 

Oem usually is interpreted as factory equivalent, but it is not always true.
On the other hand they can be better.
I was the product manager for an OEM system sold to MB. They are a demanding buyer, but that does not mean they always buy the very best.

 

MBZ doesn't make a lot of its own parts. It sources them from suppliers. When they end up in MBZ factories and dealership parts shelves, they bear the three-pointed star logos and MBZ part numbers. Those OEMs are generally not prohibited from making their own versions of those parts. They should be of equal quality to MBZ-branded parts. For example, Mann oil filters. There are some parts that I would not buy "aftermarket", but others I wouldn't worry about at all. Cabin air filters, wiper blades, bulbs, etc. are no worries, but oil filters, suspension parts, electronics, etc. are all critical enough that I only buy genuine (or known OEM, like Mann oil filters).

 

Rudeney: So, you will use the Mann oil filter?

Autohausaz
Mann OEM HU7185X
Oil Filter Kit; Polyester Fleece Media, Extended Service

As a side note, I also bought Mann air filters from the same site. The feel and appearance of these Mann air filters are exactly the same as MB.

 

Yep, I use the Mann synthetic fleece oil filter and their engine air filters.