Auto Parts: Dealer vs. Aftermarket

The question of whether to buy 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 things worth considering to help you make a better choice if you're facing that same question.

Automobile manufacturers and dealerships always 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 every rubber gasket, spring, screw, plastic part, and metal component that go into the part 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.

Automotive Parts
Genuine Factory Parts and Approved Accessories

Genuine factory parts are advertised as better than anything else, and worst-case scenarios of aftermarket parts failing, not fitting, or causing other problems are cited eagerly 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. Often, the markup is 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 parts on older cars involving electronics become extra inflated due to lower production. But that's the hype from dealerships. Reality is there are excellent aftermarket parts on the market, and there are just as many not-so-excellent ones.


OEM vs Aftermarket

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.

Parts manufactured by aftermarket manufacturers were not actually authorized to be 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 give a black eye to the aftermarket industry as a whole.

Maintaining Factory Warranties On Newer Vehicles


New car manufacturers typically provide bumper-to-bumper warranties for three or four years on newer cars, and may continue coverage of certain items for up to six years on vehicles bought with a Certified Pre-Owned warranty. Additionally, some powertrain warranties cover running gear such as internal engine, transmission, and drivetrain components for longer amounts of time. When warranty coverage is involved, new car manufacturers always want the failed parts shipped back to them. They will automatically reject coverage if a failed part is an aftermarket one, or the part in question failed because of a connected aftermarket part elsewhere.

The Magnuson-Moss Act of 1975 set guidelines for manufacturers selling products in the United States. One of the things it did was state that is illegal for a manufacturer to void your warranty or deny coverage under the warranty simply because an aftermarket part was used. However, a dealer/vehicle manufacturer does have the right to deny a warranty repair but they must demonstrate 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 actually improve on flawed OEM part designs. For example, many companies specialize in Jeep and other 4x4 parts that are made with more expensive materials for the express purpose of being stronger. Components designed to replace undersized suspension parts, tailgate hinges, hood latches, and other items that routinely fail over time because the factory opted to save money producing them. Another example is the wealth of aftermarket companies that build replacement air springs for German luxury cars which improve on original design failure points.

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 marked up by a dealership. There's also a wealth 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?

After ten years, new car manufacturers are no longer required by law to produce OEM parts for older models. When demand for OEM replacement parts drops, the profit margin of keeping and running stamping dies and machinery to make them is eaten up by paying for space, labor, and inventory. Because that same space is more profitable when devoted to current-model production in greater volume, they'll focus on that instead. Automotive body panels are a prime example of OEM parts that are harder to find, and one of the easiest areas to find poorly shaped and sized parts that don't fit. Aftermarket body parts are one case for accepting ones that are nothing less than the highest quality. They're 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, trading, or junking 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.

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 is the most preferable option if you only own one car, it's apart, and you cannot use it until a repair is complete. Large aftermarket parts chains are the safest bets because they have more experience weeding out better part manufacturers from bad ones. They'll usually provide a fair return or exchange policy and they'll treat you well to ensure repeat business.

However, smaller independent stores can offer a positive experience also, and they're more likely to be owned by knowledgeable folks who have worked as mechanics themselves. 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're only hearing one side of a story when there's dissatisfaction.

The Parts Store

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. If you're looking at a part for a car that wasn't a best-selling model, chances are lower parts demand means what you're buying has probably been sitting on a brick-and-mortar store shelf longer. Years in some extreme 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 test their website by selecting a variety of vehicle makes and models. Product descriptions, pictures, and applicable specifications should vary at least somewhat with each change. If you see zero variation, the retailer hasn't taken the time to thoroughly learn about what they are selling. This increases the chances you'll make an incorrect choice because you're uniformed, or you may be sent a part that doesn't fit your vehicle due to the retailer's error.

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.

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