Are Genuine Auto Parts Better than OEM Car Parts and the Aftermarket Segment?


If you’ve ever looked into automotive replacement parts, the chances are that you’ve heard the terms ‘genuine auto parts‘, OEM car parts and aftermarket replacement parts. Many drivers mix these and don’t really understand the difference between each of these terms.

Our goal today is to fix that. We’ll go over each of these categories and explain what they offer. By the time you’re done reading this guide, you’ll have all the information you could need to shop for parts in the future!

The Development Path of Car Parts

Designing a car takes a lot of engineering. It’s not just about putting together an engine and making it fit into a chassis. When a new vehicle is ordered, engineers are presented with a curious task of either reusing some of the existing parts from other models, which isn’t uncommon or coming up with brand-new parts.

Either way, the car manufacturer themselves has to manufacture a certain number of parts. The issue is that most car manufacturers don’t have the facilities to mass-produce automobile parts. That task is left to 3rd party contractors who have the production lines already set up.

Genuine Parts Explained

Genuine Parts Explained

When automobile manufacturers order parts from 3rd party contractors, those parts are generally labeled with the automobile manufacturer’s logo. Such an automobile part is what you call a ‘genuine auto part‘. Genuine parts are made to the original equipment manufacturer’s specifications and meet all the requirements and quality control standards.

Mind you, some of these QC processes and standards are nothing to joke with. The idea is that a genuine part will last as much as the part your automobile came with from the factory. After all, they are the same thing. Such a level of strict quality control is the main reason why genuine parts are often on the expensive end of the scale.

You’re definitely paying a premium, but you’re getting a good warranty as well as the knowledge that your new part is every bit as good as the one that failed after hopefully a lot of use.

OEM Parts – What’s the Difference?

Next, we have the OEM parts. Contrary to popular belief, OEM and genuine parts are not the same. However, they are incredibly similar.

When automobile brand orders genuine replacement parts to be made, they often expand the contract to include OEM parts’ production. OEM parts are the same part as the genuine part, only without the car manufacturer’s logo. One good example is BMW and Lamfoerder.

BMW has contracted Lamfoerder to build genuine parts for them, all while allowing Lamfoerder to sell the exact same parts under their own brand.

When it comes to pricing, OEM parts are generally cheaper than genuine parts. They’re often less expensive because they lack the extended warranty you get with the genuine variety. OEM still comes with some type of warranty, but it’s not as generous.

Fitting OEM parts on your automobile won’t leave you vulnerable in any way. You’re not shortening the lifespan of your vehicle, nor are you ‘cheapening out’ on automotive maintenance. Dealerships often use OEM replacement parts in place of genuine ones when you go in for service if genuine is not available.

You can rest assured that OEM products are more than fit enough to keep your vehicle moving reliably.

OEM Parts - What's the Difference?

Aftermarket Parts – The Wild West of Automotive Spares

Last but not least, we have the aftermarket segment of automotive parts. All kind of stuff is being sold in this segment. Aftermarket replacement parts can be as good as OEM, or they can be inferior. On rare occasions, the aftermarket part can be even better than OEM or a genuine one.

There are known cases where the genuine part has proven to be underbuilt after years of use, prompting aftermarket manufacturers to kick things into gear and find a better solution. One such instance that comes to mind is the intake manifold lever on M272 and M273 Mercedes engines.

The original component in question was made of plastic that would often fail after years of use. Aftermarket companies such as URO went on to build much better, aluminum intake manifold levers. As it turns out, using an aluminum lever not only fixes the problem but also prevents it from ever happening again.

That being said, aftermarket replacement parts can cause harm as well. The fact that quality control is often non-existent, some aftermarket parts don’t meet even the most basic standards for durability. You’ve got companies that cheap out on materials to be more competitive, thus leaving room for potential premature part failure.

The lesson to be learned here is that you need to approach the aftermarket segment with a lot of caution. It pays to stick to proven brands that are known to deliver quality. Don’t be tempted by too cheap replacement parts made by companies you or anyone else has never heard of.

Even if that cheap part looks like it’s built using decent materials, there’s still the matter of tolerances and the acceptable margin of error.

Bottom line, you get what you pay for.

How to Recognize Quality Aftermarket Brands?

How to Recognize Quality Aftermarket Brands?

If you got discouraged by our talk about aftermarket parts, don’t be. There are plenty of quality manufacturers out there, and you likely know many of them already. Brands such as Koni or Sidem all fall within the aftermarket category. Needless to say, Koni is a proven company, and you can rely on them to deliver quality suspension parts for your car.

The world of aftermarket parts isn’t interesting just because you can potentially find better quality than OEM. It also gives you the means of expressing yourself in your car. A good example that comes to mind is silicone hoses. These come in all kinds of colors, allowing you to spice up your engine bay, all while improving your system’s reliability.

Things get even more interesting once you move into aesthetic upgrades such as various body kits, trim details, and a whole array of other interesting things.

How to Find Genuine, OEM, and Aftermarket Parts?

If you’re looking for quality genuine, OEM, or aftermarket parts for your car, you’re in the right place. We offer a wide range of products for European brands such as BMW, Audi, VW, Mercedes, Porsche, etc.

To find the parts that fit your car, simply input your car’s make, model, and year into your system, and you’ll get a list of matching products. You can also narrow down the search by using our VIN tool. This way, you’ll get more accurate data for your specific vehicle. Just keep in mind that our system only accepts US VINs at the moment.

If you have any further questions regarding our offer, feel free to contact us via email or by phone. Our customer support service reps are standing by to offer assistance and answer any questions you might have regarding our catalog.

eEuroparts.com takes pride in being a company of petrolheads. Our customer support service reflects that by being staffed with enthusiasts who know their stuff.

7 thoughts on “Are Genuine Auto Parts Better than OEM Car Parts and the Aftermarket Segment?
  1. I know that the difference in price for the lower control arm on a 1999 saab 9-3 “Genuine Saab” vs. Aftermarket is huge! I purchased the aftermarket one and I am very happy with it. The ball joint on it seems to hold up just fine. On the other hand, I purchased a timing chain/balance chain kit, with all the sprockets, sliders, balance chain tensioner, cam sprockets, for a very reasonable $209 (Genuine Saab). There are some places that you don’t want to skimp on, and timing components are one of them! I highly recommend this kit! Eeuroparts.com is the best in the business!

  2. sonia

    the info was helpful as I recently purchased wipers for my Saab and they came in two different boxes. I thought you guys made a mistake in the shipping and was planning to write to you about it.

  3. Art's Ai photomechanical

    I really like eEuroparts, they get 98% of my business. The reasons are many – here’s three; 1) They aren’t overly diversified & know Swedish machines better than anyplace else. 2) Their website is VERY good, making others look plain ridiculous. 3) They ship incredibly fast…usually getting a box on my doorstep in under 48hrs, often the next day (with “regular” free over $50 shipping), it’s really amazing.

    I like eEuroparts so much that I continue my patronage despite several bad experiences with aftermarket parts they’ve sold me that didn’t hold up. I’m a devout DIY guy & also in the “word of mouth” repair business. As anyone else, I’m pretty miffed about getting stranded & doing time consuming repairs twice due to substandard parts. I keep some parts “in stock” in anticipation of needing them…& am sitting on some stuff I don’t dare use because previous experience has proven I’ll be sorry. Here are some parts I’ve been boned by:

    Red polyurethane alternator mount bushings (absolute junk, disintegrate in 3-6 months). ScanTech turbo bypass valves (garbage) & heater valves (never last more than a year). Unknown brand serpentine belt pulleys (the plastic fell apart after less than 20k mi…bearing still fine, but needed a tow truck). Wahler thermostats (good quality, wrong size). Unknown brand timing chain slider (didn’t fit).

    Lastly, I’ve had a few occurrences of parts not being listed, but subsequently appearing as “other parts you may need” AFTER my order has shipped. Recently, eEuro’s customer service told me I’d have to place another $50 order to get the $5.74 clutch master cylinder rebuild kit that mysteriously became available the day after I placed my order, without incurring $8.95 to ship it. That was extremely irritating…eEuro’s customer service used to be much better. It’d also be nice to have a better selection for certain categories – brake items for instance (esp pads & rotors)…silicone vacuum hose would be nice too. I offer my criticisms in the hopes eEuro may heed them & take necessary corrective action. I look forward to receiving an email.

    Art, Ai Photomechanical

  4. Ed A.

    I purchased an after market ignition cassette kit from eEuroparts for $216.00 including shipping.

    This is the first after market part I have purchased for my 2002 Saab 9-3 convertible. The discounted cost for the original equipment part is $379.00 and then add in the plugs and grease. Since the after market company is Swedish and came from eEuroparts I felt it was worthy of my trust. Now I feel I may have been naive and made the wrong decision. The original part was replaced before failing at 50,000 miles with an original part, it just failed at 112,000 miles. Will I get the same service and miles from the after market cassette? your article is helpful but I wonder now if I made the right call.

  5. Pingback: Get It Right The First Time: Finding Correct Parts At A Fair Price - BimmerLife

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