OEM vs Aftermarket: Are Auto Parts Created Equal?

Being in the aftermarket auto parts bizzz, I often find myself verbally battling with guys that are hardcore OEM auto parts only.  They usually say “I only buy OEM auto parts because “aftermarket stuff” never fits, works, lasts, etc.”  They usually have an example of a part that they bought from a local auto part store that didn’t work out for them for whatever reason.  Fair enough, we’ve all been there.  Now, I have absolutely no problem with OEM parts by any means.  In fact, before working for 1A Auto, I was a technician at a Cadillac dealer using all OEM parts.  Needless to say, I’m quite familiar with a wide range of auto parts.  Do bad OEM parts exist?  Absolutely! (Just ask anybody that has owned a Cadillac Catera (Sorry, I had to…))  Do bad aftermarket auto parts exist?  Absolutely.  However, not all auto parts are created equal. So let’s talk about it.

We’ll start our examples with a company that does really exist and everybody knows of them because they make absolutely fantastic suspension products.  I’m leaving the name out because the auto parts that they build are more relevant than their name.  For now, let’s call them “Company X”.   Now, the way I understand it, about 50% of the suspension parts that Company X produces are OEM parts for brand new cars.   Naturally, they also produce extra’s for the car dealer’s to stock in their parts departments.  It would be in an OEM brand name box, but it is actually built by Company X.  When the OEM’s need a part produced, Company X  is given specs by the vehicle manufactures and as you may guess, they build these auto parts to the exact specifications that they are given.  The OEM engineers really only need these parts to last as long as the car’s suspension warranty, without compromising safety or their own brand name in the process.  All the parts function as they are designed to, but long term, some parts are better than others.

The other 50% of the auto parts that Company X produces are what I call “high quality aftermarket auto parts”. They are Company X’s aftermarket brand, built to their own specs, which are vastly improved over the OEM parts (if they need to be).  They find the faults of the original designs and they correct them for their aftermarket brand because Company X wants them to last forever.  Everything is greaseable (as suspension parts should be), and engineered to be better than the OEM’s originally wanted. It may be a visible change in the look, or it may look identical and be internally changed. In some cases the OEM part doesn’t need to be improved upon, and the high quality aftermarket part brand is the same exact part as OEM but without the part numbers marked on them.

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On the other hand, there are the cheaper options available out there which I call “low quality aftermarket auto parts”. These are typically the ones that can give “aftermarket parts” as a whole a bad name.  The reason that they are the cheapest price is because they are the cheapest to produce.  Being the cheapest to produce rarely equals the highest quality.  The unfortunate truth to these parts is that you don’t really know if this is the part that you are buying until you attempt to attach it to your car. Before long, you need torches and welders to make it fit, and you need a new one in a few weeks.

Now you can’t talk about OEM vs Aftermarket auto parts without talking about price.  Here’s the way it works.  Since the average consumer can only buy OEM parts through car dealers,  the dealers can charge a premium.  There is typically minimal price differences between dealers because their doesn’t need to be.  They control the flow of OEM parts.  Aftermarket parts are different because you can have multiple manufacturers of similar products.  You can count on all of them being priced less than an OEM part from a dealer, but the quality can vary greatly.  High quality aftermarket parts are priced far less than the dealer, but sold from a variety of different outlets which means competition and a super high quality part at a competitive price.  Then there are the cheap (and I do mean cheap) low quality aftermarket parts.  They will be priced the lowest, and may or may not be what you want when you open the box. “EEEK! What is that!?”

So although my opinion may appear to biased because of my position, I’ll give it to you anyway.  I prefer the high quality aftermarket parts over OEM because I know what goes into them, and the price is right of course.  Want more? Ok, fine. Recently I installed some new ignition coils in my wife’s RX8 as a general maintenance procedure.  I took a few pictures for OEM vs aftermarket comparisons.  The new ones were perfect in  every way, and the RX8 is happier than ever.  (OEM’s are on the left side of the picture, and the 1A Auto coils are on the right.)



So how do you tell a quality aftermarket auto part company from the others? Take a look at what else they have to offer you, including warranties and guarantees, USA based customer service, installation videos, engaging blog articles and other automotive content, etc. If it looks like they care, they probably do.

Jeremy Nutt

Hi, I'm Jeremy.

39 thoughts to “OEM vs Aftermarket: Are Auto Parts Created Equal?”

  1. I think it was Consumer Reports that did a test years ago on sheet metal, and the aftermarket piece way out lasted the gm oem door skin in an environmental exposure test.

    1. What ignition coil should I put in a 2011 Ford Explorer limited it only has 70.000, I have a check light , error code po 306 miss fire on 6

  2. Which are the BEST aftermarket companies or product names? I can’t find say….brake pads tested, these are the highest rated brands. I have a Volvo, and anytime I deal with the dealership it is a nightmare. Once, I had to wait 40 days for a part to come from Sweden. The car broke down on day 42 and I had to be pushed into a graveyard to wait for a tow truck… What are names I can trust, Please? Thanks

    1. Hi Ruthlee,

      Waiting in a graveyard for anything is never a good sign! It’s as if the car was trying to tell you that its time was up! 🙂

      As for your brand question: There are so many parts out there that it really depends on which part that you looking for. With fear of sounding like a sales pitch, finding the best parts for our customers is what we do really well here at 1A Auto (I know, very sales pitchy, but bare with me, it will come full circle.) See, unlike many businesses that sell auto parts, we are real car enthusiasts here. We work on our own cars, and we make our own how-to videos, so we know a high quality part from a cheaper low quality one. (I literally had a VW engine out and apart in 1 million pieces 3 days ago, my hands are still dirty! 🙂 ) So what I’m getting at is that we do all of this painful detective work for you. We separate the good parts from the bad, and then we don’t carry the bad ones because well……they’re bad.

      Many people out there love OEM parts because they know that it will be just like the part that they are taking off their car. The downfall / devil’s advocate is: The OEM part has already failed you once, so does buying OEM again really make sense? Answer: Yes and no (of course!). It really depends on a million factors – What part is it? Is it a part intended to wear out? Is OEM the only option available? Etc. Sometimes OEM is the right choice, but certainly not always.

      So listing good brands vs. bad brands is really tough for the aftermarket auto parts industry as a whole. I can tell you that businesses that care about their customers and the product that they are selling will likely carry the parts that are known to work. My advice on buying the absolute best auto parts is first off, figure out which part you need (that’s the tough part!). Then research where to buy it. There may be several businesses that have the part, but not all of them put their own faces on the front page of their website, make how-to videos to show you how to install it, and have ASE certified customer service people to help you out anytime you need it.

      Sorry, was that too sales pitchy? 🙂 Honestly, if you have any questions about any specific parts or brands, everyone here will happily answer every question you have. Naming all the good brands would be quite a challenge though!

      1. Hi….I am presently going through a major problem with an aftermarket idler arm for a Dodge Ram van . I bought it through a shipping dealer in Florida. It did not fit correctly and it broke the ball-joint . The o.e.m.parts are on back-order for weeks at Dodge……….fortunately ,I was lucky to find a California Dodge dealer that had one from old stock ,and it is in the mail …..my van has been of the road now since xmas….part of the problem with aftermarket parts too is : the automated sights on-line provide false information about the fitment of parts to your vehicle .Even if the part looks exactly like the o.e.m. ,the specs can be incorrect and of course the buyer won’t know that until it is delivered ,which is what happened to me . Any way ,thanks for listening Frank.

      2. Was wanting to know if you know anything about Mevotech and if they a good company to use? I order their upper control arm, both sides, and installed them. Haven’t yet been on the road for I also need a pitman and a idler arm. There parts seem to look like good quility but I also know that doesn’t mean Jack. Any insight on the company and the craftsmanship of their parts would be great full. Thank you

  3. Hey Jeremy,
    Do you think that the CAPA certification process will resolve this issue or highlight exactly which aftermarket parts suppliers give the industry a bad name? Is this a good solution, in your opinion?


  4. Here is my question: How does a manufacturer (aftermarket) get the specs to make the part?

    in this case I am talking about a company that is not mass producing “OEM” parts as well as supplying to aftermarket.

    1. Hi Josh,
      I’m under the impression that they reverse engineer it somehow, though I don’t really know the details of how it works. I imagine lots of measuring or scanning with some awesome machines, though maybe that’s just in the movies…

    2. The OEM contacts to the manufacture of said part to build the part needed. This manufacture is not only an OEM supplier (Tier 1) but also could be the same manufacture supplying the aftermarket under their name. Standard Motor Products, Federal Mogul, Akebono, all are Tier 1 OEM manufacturers who sell also in the automotive aftermarket.

  5. I want to be positive here, but this article didn’t really tell me anything helpful. I still don’t know what aftermarket parts are good, just that “some” are.

    The reason I stumbled upon this artical is that a few weeks ago, I bought some Mevotech greasable ball joints for my Corolla off a seller on Amazon. Unfortunately, they sent me Mevotech’s Asian-made Chasis Rite line of greasable ball joints with almost the identical p/n on a different box. I complained and for another $13. they sent me my Mevotechs. Weird thing is, they’re identical to the Chasis Rite (which they didn’t even want back) parts in every way. I understand that there can be internal differences and differences in metalergy and polishing, but I’d bet my right arm they’re identical. If that isn’t confusing enough, the Chasis Rite box says “Made in Taiwan” and the Mevotech box says “Made in China”- I was led to believe that Mevotech is supposed to be made in the USA, that’s one of the reasons I went with them.

    I have a friend in the auto parts biz that says every auto part is made in Asia (mostly China) now. He also says this metal to metal ball joint receiver that the Mevotech claims may not be as good as a ball that sits on a nylon or plastic race of some kind, and just because it’s greasable (which I will grease several times a year) isn’t necessarily as good as non-greasables. I sorta diagree.

    Any genuine comments on all this would be VERY helpful and appreciated. Dean

  6. It is hard the find reliable auto parts , I personally buy a from 1A auto parts as long as they have the parts I need, which is often, I keep a list of places I use and how reliable there parts where, and how they fit, and as well, how long they last, so before I buy auto parts, which for myself is all week long. I go to my list of favorite part dealers, I rarely go to a car dealer ship for parts , as for the most part they are junk, Dealer parts are not made to last, engineers get paid a lot of money to make sure that the parts only will last a certain amount of time. (fact, sorry to say)Dealer parts are fine when your trying to keep a special car stock, and it hardly gets drivin…what I,m trying to say is….do your research, and keep a log of good, and bad experiances with auto parts..you,ll save your self a lot of future grief….

  7. My front bumper in my 2011 camery was hit. His insurance will pay for after market not stiock is it worth me paying the difference on this one?

    1. Hi Chris,
      I would bet that if you have a good repair shop replace the bumper, you won’t notice a difference between OEM and aftermarket. I believe that most insurance companies will only use CAPA certified parts anyway (http://www.capacertified.org/) which means the parts are randomly tested throughout the production process for a variety of quality checks. I think more importantly than aftermarket vs. OEM, you should be sure to find a reputable shop to do the work. Quality labor goes a long way!

      Good luck!

  8. Okay, good generic write-up, but I wish I knew what your Brand “X” was. I’ll give you one that has failed to explain and back up their product.

    I ordered MOOG upper ball joints for a ’97 Tacoma 4WD (Yes. MOOG. Wow, WERE NOT WORTHY! ha, b.s.) They looked fine, had a grease zerk, and felt sturdy. BUT THE UPPER COLLAR THAT THE DUST BOOT MOUNTS TO IS A LARGER DIAMETER THAN THE MATING SPLINES ON THE BALL JOINT. When I placed them in the flange of the steering knuckle, it seemed obvious that I was about to ream out and ruin the steering knuckle.

    The Tech Support department of the vendor I bought them from could not verify which would deform first, the upper collar of the ball joint, or the steering knuckle. Happily, they are willing to accept returns. MOOG’s website sent me a “Thank You” email for my concerned request for answers, but never responded in two days, and probably NEVER WILL. Darn Right, I am sending them back. As an example, this aftermarket company should be more willing AND ABLE to support its products and explain them.

    So, it looks like OEM upper ball joints. 250,000 on the originals, Oh what a feeling! Let’s hope the MOOG lower ball joints fit better, or they’re getting returned also.

    1. Hi T-L!
      Thank you for sharing your experience on the topic! It’s a drag that you are having trouble with your ball joints, and I share in your pain because I have definitely been there before. MOOG typically does make some really nice parts, but unfortunately nobody is perfect. Auto parts are a tricky animal because car manufactures do crazy things like change parts mid way through a production year, and sometimes carry over old vehicles even after a new body style is released (like the Malibu Classic, and Ford Heritage edition). This makes cataloging parts incredibly complex. In your scenario, it could be that the part was boxed wrong, maybe they were built wrong, or they could have the wrong “vehicle fitment” interchange associated with it. Your truck is a 97 though, which is smack-dab in the middle of a body style, which usually means aftermarket parts are more likely to fit right. The beginning and end years of a body style are usually the confusing ones. Whatever the case may be, I hope you get it resolved soon. As I said, I’ve been there.

      Thanks again for sharing your story with us and feel free to keep us updated with your results.

  9. One needs to seek advice, and be diligent as needed, with either local service, dealerships, online, etc. Moog appears to be a very different company from even 5 years ago, and older reviews and raves mean little nowadays. Asking local independent shops as to their own preferences within each part category may be helpful, as they must deal with negative feedback and bad word of mouth. Just replaced two front CV axles on an ’02 Forester; one was the 13 yr old original, the other just a two-year-old aftermarket replacement – which fortunately was warrantied by the local parts shop/mfger of rebuilt CVJ. OEM Subaru parts overall hold up quite a long time, but even their replacements may not always be the same as original after 10-15 years. One indy advised buying only OEM strut boots, as aftermkt weren’t very good; so many things, especially suspension or electrical, can be hard to compare, and installation costs more versus even the priciest part, so false economy sometimes enters in need for re-servicing, even if the part is ‘warrantied’.

  10. Thanks Jeremy, that is a very helpful description of the aftermarket parts business. I’ll be ordering some suspension parts from 1A.

  11. Hi Jeremy
    I am involved on a forum where someones aftermarket pitman arm failed. Fortunately it happened in a driveway and no one was injured.
    Now we are seeing pictures of all kinds of pitman arms for the same cars that aftermarket suppliers are providing. This is being escalated by people who purchased what looks like poor quality arms. There are pictures of all kinds of the same arms that have the ball pin peened over on the bottom and some welded and some have nothing done to retain the pin.
    What is the quality control and/or design process of big after market parts suppliers/producers?
    My question specifically applies to a part like this that would be classified as critical.

    1. Hi Don!
      Do you have a link to the forum with all of the info? We would love to take a look at it and see if we can help further! As for the quality control – I think it really depends on the company that produces the part. Auto part manufacturers that are larger (typically) in size and want to grow/exist in the future all have in-depth testing procedures for everything that they produce. We, at 1A Auto, visit these facilities on a regular basis, to make sure that the company has a healthy work environment for their employees and is also producing the highest quality products that are being tested before they ever reach our distribution centers. So while I don’t know the testing procedure specifically for the pitman arms, I know that they are being tested. Send me a link to the forum thread, and maybe I can get some more details on the specifics for you guys.


  12. Hi I am hoping this forum is still being monitored as I need some assistance. Local dealership is trying to take advantage of me on replacing a couple of items on my 2000 Toyota RAV4. Based on my research they are jacking up costs of parts by around $400. Currently undergoing expensive medical treatments and just cannot afford $1000 repair but I need reliable transportation to get back and forth to my treatments. Could you recommend a good aftermarket manufacturer for an EGR valve and and air/fuel ratio sensor? I would be very grateful for the help.

    1. Hi Karen,
      Sorry to hear about the expensive repair and the expensive medical treatments. Typically dealerships are more expensive than independently run auto repair shops (in their labor rate and parts), so it may be worth trying to find a local independent garage than you can trust for future repairs. That will save you some cash for sure. Another option is the buy the parts yourself and bring them to a trustworthy auto repair facility of your choosing to have them installed (dealership, independent garage, talented backyard mechanic, do it yourself?). If you decide to go that route, we actually have all the parts that you need for far less than your quote. Below is the info you need whether you buy the parts from us, or anyone else:

      EGR valves recirculate Exhaust gasses back through your engine, essentially burning the “air/fuel mixture” twice at highway speeds with the goal of lowering exhaust emissions. When they fail, they can fail closed, and will typically just turn on your check engine light. The other possibility is that they fail open, and make your engine run terrible and stall out, in addition to turning on your check engine light.

      If your Rav4 is a 2.0 engine with an automatic – this is the EGR valve you need https://www.1aauto.com/toyota-camry-rav4-solara-egr-valve/i/1aegr00008?f=310528&y=2000
      If your Rav4 is a 2.0 engine with a manual transmission – this is the EGR valve you need https://www.1aauto.com/toyota-camry-rav4-solara-egr-valve/i/1aegr00009?f=302270&y=2000

      The Air/Fuel ratio sensor is also known as an “oxygen sensor” or “O2 sensor”, and it measures the amount of oxygen in your exhaust system, which in-turn allows your engine’s computer to adjust settings and make the engine run better/cleaner. When they fail, they often make the engine run “rich” (burning too much fuel), and turn on a check engine light.

      Oxygen sensors are a bit more complex to buy because you didn’t specify which sensor you needed, and there are two oxygen sensors on your vehicle. That being said, I’ll happily make it easy for you! When buying an oxygen sensor, you’ll find that you need to know if you need a “Upstream” or “Downstream” sensor. The “upstream” oxygen sensor is before your catalytic converter. The “downstream” oxygen sensor is after your catalytic converter. The catalytic converter is usually the first big bulge in your exhaust system, up closer to your engine, not to be confused with your muffler near the back of the car. I imagine that it probably specifies which oxygen sensor you need on your dealership quote (hopefully it does!). The other slightly tricky part of oxygen sensors is determining whether your vehicle has California emissions equipment on the engine or not. This is pretty easily determined by opening your hood, and looking for a rectangle sticker somewhere under the hood that says “This vehicle is equipped with California emissions”. The other option for this sticker would be something like “This vehicle meets all federal emissions requirements”. So – once you know whether you need the upstream or downstream, and federal or California Oxygen sensor, you can call us up at 888-844-3393, or order it right on the website here: https://www.1aauto.com/2000-toyota-rav4-oxygen-sensors/y-mo-c/2000-399-72

      Once you have the parts, you can bring the parts to somebody to install them for you. Once the parts are installed, the technician will need to erase the codes that cause the check-engine light on your dash. Then you’ll be good to go. Saving money!

      Good luck and feel free to keep us updated!

  13. Hi Jeremy,
    thanks for the write up. Several years later and this is still helping us. I’ve been wanting to pull the trigger and buy a ball joint and control arm set from 1Aauto (that’s you guys!) but i’m nervous as I don’t see a brand and don’t know the quality of these critical suspension components. I think the price is great but what about quality since my family’s life depends on it. Can you help me? here is the link

    1. Hi Ronnie,
      Thanks for checking out the 1A Auto blog post! Rereading this post actually makes me miss my ’05 Mazda RX8 a little bit. It was truly a fantastic car that I had so much fun with, but I sold it a couple of years ago to get a more economical vehicle. Hopefully I’ll get another RX8 some day…

      As for your question – I completely understand your concern about buying a suspension part as important as a ball joint. While we don’t have a brand attached to this specific part (other than it being from 1A Auto), I can tell you that we do physically travel all over the world to visit the factories that build the auto parts that we carry because we want to make sure the quality is where we need it to be. In fact, we have an entire department dedicated to quality. We would much rather not carry a part at all, than carry one that isn’t up to our high quality standards. The other thing that we do is test fitting many of the parts on cars to make sure they fit and function as they should. You can see an example of this, with this specific ball joint right here: https://www.1aauto.com/how-to-replace-install-front-ball-joint-2001-05-honda-civic/video/9593 We hope that the combination of all of this will ease your mind a bit, and empower you to take on some auto repair tasks that you may not have attempted in the past. Lastly, we do have a customer service center here in Massachusetts that can answer any questions that you have before, during, or after the purchase. Call, email, or chat with us anytime! 🙂


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