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Auto Parts: Dealer vs. Aftermarket

OEM parts certified by automakers as "authentic" have advantages - and high markup. We discuss cases where aftermarket parts do & don`t measure up, and how to pick quality ones.

The question of whether to buy replacement parts from an automotive dealer vs. ones from aftermarket manufacturers is as age-old as the automobile itself. Below, we'll take a look at criteria worth considering that will help you make a better choice if you're facing that same question.

Automobile manufacturers and dealerships advertise the fact that their parts are "genuine" because they were made by the exact same production facility that made the parts installed on the assembly line. That implies all parts for engine, suspension, body panels, driveline, electrical, and other areas are stamped by the same machines that made the originals, and that they match the original part's tolerances when it comes to thickness, tensile strength, size, and clearance.

Genuine factory parts may be advertised as better than anything else, and worst-case scenarios of aftermarket parts failing, not fitting, or causing other problems are sometimes cited as selling points. While that may or may not be true in every instance, dealerships apply significant markup on every part sold to cover expensive overhead costs.

The markup can be 100% over their cost and sometimes more when it comes to lower-priced items such as nuts/bolts and trim pieces. Quality aftermarket parts are an effective way to save money, especially when it comes to older cars modern enough to be equipped with engine control modules, transmission control modules, body control modules, and various related sensors. Electronic components are expensive to produce, and even more expensive to purchase when they become extra inflated due to lower production. But that's the hype from you may see. Reality is there are excellent aftermarket parts on the market, and there are just as many not-so-excellent ones.


Parts built by the exact same manufacturer that made the ones originally installed on your vehicle when it was built are known as "OEM", signifying they are made by the original equipment manufacturer. Whether they were built by the automaker themselves or contracted to an outside supplier to build, they are fully authorized by the carmaker as "genuine" or "authentic".

The expression "OE" (signifying "original equipment") is used in the business just as often to signify a genuine or authentic part. Dealership parts departments and manufacturers use the term "OEM" when they refer to parts the vehicle manufacturer authorizes, so that's what we'll go by for the purposes of this article.

OEM vs Aftermarket

Parts manufactured by aftermarket manufacturers were not actually installed as original equipment on new car assembly lines, but they are designed to match (or approach) manufacturer specifications when it comes to looks, dimensions, and function. In other words, they resemble the original parts on your vehicle. Some of them feature improvements over OEM designs, and others of lower quality can unfairly create a bad reputation for the aftermarket industry as a whole.

Maintaining Factory Warranties On Newer Vehicles

Car manufacturers provide bumper-to-bumper new car warranties, typically for three or four years. Additionally, some powertrain warranties cover engine, transmission, and drivetrain components for longer periods of time. Certified Pre-Owned (CPO) vehicles can have warranties that extend out six years or more from date of first delivery.

When warranty coverage is involved, the vehicle manufacturers almost always want the failed parts shipped back to them. If the manufacturer or its authorized dealer has reason to suspect that installation of an aftermarket part was in any way related to a failure, they may try to deny the claim under warranty.


The Magnuson-Moss Act of 1975 set guidelines for manufacturers selling products in the United States. One provision of the Act makes it illegal for a manufacturer to void your warranty or deny coverage under the warranty simply because an aftermarket part was used. This alone should ease your mind regarding the use of aftermarket parts on a vehicle still under warranty. However, a dealer/vehicle manufacturer does have the right to deny a warranty repair if they can prove that the aftermarket part caused the problem.

Are Aftermarket Parts Okay?

Aftermarket Parts

As a company made up of automotive enthusiasts, we ask ourselves this question all the time when buying parts for our own cars. A large number of aftermarket manufacturers are genuinely interested in making quality products that can improve on less-than-perfect OEM part designs. For example, many companies that specialize in Jeep and 4x4 parts will manufacture parts from heavier-duty materials expressly to make them stronger than original ones.

Beefier aftermarket components are designed to replace suspension parts, tailgate hinges, hood latches, and other items that can fail because the factory opted to produce them to meet “minimum spec”. Another example is the number of aftermarket companies that build replacement air springs for German luxury cars which improve on known weaknesses in the original designs.

Well-Made Aftermarket Part

Plenty of well-made aftermarket parts are out there, and you can find them if you look. Manufacturers of such parts will usually make a point of telling you these things, and they often cost less than the unimproved parts at the dealership. There's also an expansive selection of upgraded brake pads, tires, wheels, fluid lines, pumps, and other components that far outperform OEM equipment when it comes to performance, longevity, noise, and other factors.

High-quality aftermarket manufacturers can always tell you about themselves in detail on their website. Any accomplishments they've been part of when it comes to competition racing, off-road challenges, or engineering work they've done alongside new car R&D departments will be clearly displayed - to name a few examples.

Reputable aftermarket manufacturers will back their product with a warranty against failure during normal use due to manufacturing defects (not abuse). Make sure you see how well each one stands behind what they sell.

What Quality Level Do I Want?

When vehicles reach ten years of age, new car manufacturers are no longer required by law to produce OEM parts for them. Demand for OEM replacement parts for ten-year-and-older vehicles naturally drops off, and it becomes financially unwise to continue production of them. Any potential profits associated with their manufacture must be weighed against the costs of raw materials, machinery, labor, inventory, and shipping. Demand is higher for parts for vehicles less than ten years old, so that will be the focus for the manufacturers.

Automotive body panels are prime examples of OEM parts that are harder to find for older vehicles. Unfortunately, it’s also all too easy to find non-OEM body parts which are poorly shaped and won’t fit well. Aftermarket fenders, doors, quarter panels, hoods, trunk lids, and similar components are perfect cases highlighting when you should accept only those of the highest quality. Such parts are out there, but require a more valiant search to find.

When it comes to aftermarket parts, quality can vary greatly. It's best to be smart and get opinions from those who have likely come in contact with them. Automotive forum pages are a great source of information when it comes to experiences do-it-yourselfers have had. If you know a mechanic you trust, ask them their opinions because they are certain to have dealt with plenty of good and bad aftermarket parts.

While it's certainly not advisable to purchase "low quality parts", there's no need to buy the best, most expensive ones either if you foresee selling or trading your vehicle in the near future. Competitively-priced aftermarket parts can be found all over, and there are many places and methods to purchase them.

"Good" vs. "Better" vs. "Best" - and Certifications that Apply To Them

On our website, some product manufacturers offers variations on a single basic item. In such cases, you'll see a drop down box in Product Options offering "quality" choices of "Good", "Better", and/or "Best". Sometimes, only two of these three may be shown.

“Good” signifies products are made of similar materials as original equipment – however materials used may differ for certain components. In short, a “Good” level product allows you to get a quality replacement that will function just like an original equipment one at a value price.

“Better” quality level means the component was built to closely match materials and manufacturing standards used by original manufacturers. They do not have certifications from major third party organizations such as CAPA (Certified Automotive Parts Association) or NSF (National Sanitation Foundation - Consumer Products Division) that set and verify quality standards in the collision parts industry, nor are the facilities that manufacture them inspected on a regular basis. However these parts may carry an independent certification that ensures the product's quality and performance.

“Best” quality level products may feature certifications from CAPA, NSF, or other agencies. Or, they may receive a designation of “Platinum Plus” and come with a limited lifetime warranty. The Platinum designation signifies a product is guaranteed to fit and maintain its appearance for as long as the owner has the vehicle. Suppliers of these parts meet all specifications and comply with all ISO (International Standards Organization) requirements. Platinum Plus parts undergo third party validations as well as internal testing to ensure that all guidelines are met. These manufacturers go through the same inspection procedures that CAPA certified companies undergo, but the inspections are performed by the manufacturer instead of an outside agency.

Note that the "quality" level reflected in drop down boxes does not always correlate with the cost. Sometimes, due to manufacturing variables such as volume, country of origin, shipping, and so on, a “best” rated product may actually cost less than a “better” rated product. Shop wisely!

New vs. Remanufactured Original Parts

For some products, it’s possible to choose either a new aftermarket one or a remanufactured original equipment one that’s been brought up to like-new condition after critical components have been made whole again or replaced. In other cases, the ONLY choice may be a so-called “reman” part, if the aftermarket is not producing new ones.

The aftermarket has stepped up with reman parts, by bringing operations in-house. Good “cores” are located, and are disassembled, cleaned, and inspected. All wear items are replaced with new, and the item is then reassembled. Depending on the part, it may also be bench-tested for performance.

Reman parts can represent a tremendous value. You’ll note that in most cases, there is a “core charge” – in essence, you are providing a deposit to the aftermarket supplier. Your old core has value to them, so once you return your old part, your core charge is refunded to you. Factory wheels are just one example of reman parts. Another example are starters and alternators, and you can read more about the remanufacturing process and core charges here.

Variety Of Remanufactured OEM Alloy Wheels
CARiD sells a variety of remanufactured OEM alloy wheels. This is just one example of remanufactured products we offer that have been brought to like-new condition after critical components have been made whole again or replaced.

If I Do Buy Aftermarket Parts, Where Should I Buy Them?

Aftermarket auto parts stores offer the convenience of getting the parts you need in your hands immediately. Naturally, this may be the most preferable option if you only own one car, it's apart, and you cannot use it until a repair is complete. (You may need to borrow a car to get there and back!) Large aftermarket parts chains may have more experience weeding out better part manufacturers from bad ones. Their size can give them stocking advantages, they’ll sometimes source what you need from a neighboring store, and they will usually provide a fair return or exchange policy.

However, smaller independent stores can offer a positive experience also, and they're more likely to be staffed with older and more experienced former technicians or parts professionals. Word-of-mouth and internet feedback are good sources of information to find the best brick-and-mortar retailer your area. However, like anything on the internet, feedback is best taken with a grain of salt because you may only be hearing one side of a story.

To some degree, automotive parts are like items at a bakery. The longer they sit on a shelf, the less desirable they become. Rubber and plastic seals dry up as they age, and time takes its toll on wiring insulation as well. These parts are known as “shelf worn”. If you're looking at a part for a car that wasn't a best-selling model, there is the possibility that a component has been sitting on a brick-and-mortar store shelf for a long time, years in some cases.

Online aftermarket parts retailers are a good alternative if you don't need parts on the same day. While some brand-name manufacturers of parts sell directly to the public, most prefer to focus on manufacturing and let other retailers handle the sales and marketing end of the business. A quick internet search of any part you're looking for will usually yield more websites of e-commerce resellers than it will of manufacturers selling direct.

E-commerce retailers don't typically stock automotive parts themselves, but have established agreements where the manufacturer ships a part fresh from their assembly line once an order is placed. The part you get will be newer without age deterioration, and it will usually be shipped within 24 to 48 hours - sometimes sooner.

If I Purchase Parts Online, What Criteria Should I Use In Selecting An E-Commerce Retailer?

Purchase Parts Online

Look for an online parts retailer who's done their homework and can provide a detailed product description of what you're buying. If you don't have prior knowledge about part's features and benefits, a proper product description should educate you about exactly what the product is, what it does, what is unique about the version you are looking at, and how you will benefit from buying it. To add to your perspective, a good e-commerce retailer will also educate you about the manufacturer of the product you're considering.

You should also be able to clearly see dimensions of the product if they are an important factor, and you should be able to see some kind of stated output if the part is a moving one such as a pump, an electric motor, or normally subjected to torque stress. If you're looking at any kind of light bulbs or lighting equipment, the retailer should be able to tell you lumen output, approximate lifespan, electrical draw, and any special features such as the ability to flash or change color.

An easy way to distinguish e-commerce parts sites that have done their homework from ones that haven't is to see how knowledgeable they are when it comes to their own products. We don’t mind pointing out our wide selection of helpful automotive articles by SAE-certified writers that have actual experience turning wrenches. More specifically, you’ll find carefully written guides on understanding benefits and differences of all kinds of products. And because we know no one is born knowing all of the details, our articles are written in an easy-to-understand format that actually proves helpful. Plus, we’ve got a lot of how-to guides and videos for installing many of the things we sell. Browse through our articles when you have some time – we’re confident you’ll find many of our topics quite interesting.

Vehicle Selection Box
A vehicle selection box will appear at the top of the screen throughout our website. This takes the guesswork out of which products will fit your ride. Simply enter the year, make, and model of your vehicle to view products specifically made to fit your ride.

Better e-commerce retailers will choose to sell products from proven manufacturers that stand behind their products with a warranty, and they will display clear details about the warranty period as well as their own return policies. If you don't find these details agreeable or you don't see them at all, you may want to try another site.

Regardless of what part or product you need, we seek to make every aspect of your shopping experience easier by making you more educated about what you’re buying – every step of the way. That’s why we back up our product descriptions and articles with knowledgeable representatives that you can call seven days a week for help with any questions – without high-pressure sales tactics. We look forward to doing business with you soon!

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All manufacturer names, symbols, and descriptions, used in our images and text are used solely for identification purposes only. It is neither inferred nor implied that any item sold by is a product authorized by or in any way connected with any vehicle manufacturers displayed on this page.