OEM v. Aftermarket Parts For Your BMW

why are bmw parts so expensive

You’ve just discovered that your fuel pump is blown. Of course you are pissed, and you have a right to be. You know a little bit about turnin wrenches so you elect to replace the pump yourself and save a couple bucks. But your frustration hits new levels after a phone call with the local dealership informs you that the OEM pump is going to be $500. Calls around to the local auto parts store reveal that Autozone is selling the fuel pump at half the OEM price. Still not satisfied, you check up online and find a “URO” brand aftermarket fuel pump for $100! Now were talking, but of course you are worried about a considerable quality difference between the $100 URO part and the $500 BMW part.

One year ago my brother was having this very debate with himself and he ended up picking the $100 URO, I’ll tell you how the story ended at the end of this article. This article will discuss the differences between aftermarket and OEM parts, my experience with online aftermarket parts, and things to consider when choosing your parts.

Aftermarket v. OEM BMW parts

When you go to the dealership (Stealership?) you know that the mechanics will be putting on OEM (original equipment manufacturer) parts. These are parts that are sourced from the car’s maker. Although just because a part is listed as OEM does not necessarily mean that it is high quality, you can be guaranteed that it will be of the same quality as the car’s original part.

So what about aftermarket parts? Aftermarket parts are any part that was not sourced by the car’s original maker. “Aftermarket” sometimes carries an undeserved reputation for lower quality, when the opposite is frequently true. Most independent shops use aftermarket parts, your typical neighborhood auto parts store such as O’Reillys, Autozone and Advance Auto’s stock-in-trade will be aftermarket parts (with a few exceptions).

OEM Pros & Cons


Warranty: I have never seen an OEM part not come with at least a one year warranty. Sometimes the warranty is lengthier than that.

Quality Assurance: You are assured pretty much the same quality as the original part that was in your car. OEM is arguably the safer choice than aftermarket for this reason. There is so much quality variability with aftermarket parts, but with OEM you are getting it straight from the BMW manufacturer that made the particular part.


Quality: Note that I said you are guaranteed the same quality as the original factory part. This does not guarantee that the part is Better than an aftermarket part or even that the OEM part is any good. Car manufacturers are not perfect, and sometimes the factory parts have known defects frequently stemming from cost-saving measures. Perfect example in my mind is the coolant reservoir tank which is made of plastic. I usually replace it with a better quality aftermarket aluminum reservoir

Price: I used to think that it was just BMW that ripped us off for OEM parts. Every part from BMW was usually at least 50% more than that of the local auto store. Then I bought a Ford and discovered that the Motorcraft part was almost always significantly more expensive than the aftermarket (although still cheaper than BMW). Although OEM parts are not always ridiculously priced, all to frequently the price quote leaves me feeling that the dealership is meant to serve people with too much money in their pockets.

Aftermarket Pros & Cons


Price: Aftermarket parts are usually cheaper, sometimes significantly more so than OEM parts.

Availability: When I buy OEM I frequently have to drive 30 minutes out of my way to the BMW dealership or I have to wait several days for shipping. The local O’Reillys down the block carries the more common parts in stock, and most uncommon parts can arrive at the store the same day.

Variety: There is a tremendous variety of aftermarket brands and manufacturers. Every autoparts store has a name brand manufacturer, and then an upper level brand such as BWD or BOSCH. The price fluctuates greatly between brands, but is still usually cheaper than the OEM.

Quality (Sometimes): The quality of aftermarket parts can be equivalent or even better than OEM. There are a number of performance aftermarket parts that I purchase from time to time such as Bilstein suspension components and polyurethane bushings.

upgraded bilstein
upgraded Bilstein’s are a huge improvement on the OE


Fluctuations in quality: Remember the bad fuel pump? Well my brother ended up replacing the fuel pump with the cheap online aftermarket part. One year later, I’m changing the pump again. Aftermarket parts can be made well and they can be made extremely cheaply. With aftermarket parts you typically get what you pay for.

Don’t try and save too much money by purchasing parts from generic brands on the internet simply because it’s even cheaper than the local autoparts store. There are certain parts that I will purchase from generic internet brands, usually they are cheap plastic pieces and individual gears that I can’t even purchase from the dealership. Anything more complex however such as a pump, pulley, or motor and you might as well be playing Russian roulette with your time and money.

Warranty Issues: Huge red flag, if a seller is not willing to stand by his part with a warranty than stay away. Autoparts stores for the most part always have warranties, but many online vendors do not place warranties on their parts. Always check for a warranty before you buy a part, a cheaply made part at a 90% discount wont have a one year warranty because they know the part frequently fails within a year.

Fitment: Here’s another issue that I have had with aftermarket parts. When you purchase from the dealer, they want your VIN and 99% of the time it’s the correct part. With aftermarkets, parts stores screw up sometimes or the part won’t fit exactly like the old one did. This might happen 10 – 20% of the time with aftermarket parts I buy. The best thing I’ve learned to avoid multiple trips to the autoparts store is to take the old part with you when ordering/purchasing the new one.

So What Should You Do?

oem v. aftermarket camshaft
An example of a part which I do not try and save a ton of $ on.

I myself rarely buy OEM from the dealership, I have had issues from time to time with aftermarket parts but the worst problems have always stemmed from my own doing in trying to buy too cheap too be true parts on the internet.

My advice is if you want to save some money, do a little bit of research on the brand part your purchasing. If it has a warranty that’s a good sign. Personally, I’m a big fan of BWD and BOSCH parts, but there are literally hundreds of other manufacturers.

Something else that I have noticed is many people have this illusory believe that OEM parts are always better than aftermarket. This could not be further from the truth, as OEM parts vary in quality much the same as aftermarkets do, you just leave with the feeling after buying OEM that it’s the same exact part you replaced.

Stephen Metellus

I am a BMW enthusiast and owner of abetterbmw.com! I have been repairing, flipping, and parting out BMWs for nearly ten years. I love these vehicles and I hope you will find my articles and YouTube channel helpful for whatever BMW project you have in store!

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