Aftermarket Versus Manufacturer Car Parts

When you take your car to the dealership's service department for repairs, you know you're getting original equipment manufacturer (OEM) replacement parts. But if you visit an independent mechanic, you're more likely to be offered aftermarket parts — that is, parts not sourced from the automaker. These typically cost less and help keep repair costs down. But a lot of people wonder: Are they inferior to "original equipment"? The short answer: Not usually. OEM parts aren't necessarily better, nor are aftermarket replacements necessarily worse. Some are built to the same quality and specs as the factory-original part. Some are even made by the same suppliers but sold under the supplier's brand or other private label.

But for any given part, a handful of manufacturers may offer replacement parts and, not surprisingly, quality varies. Note that even if you visit an independent shop and it recommends aftermarket replacements, you have a right to request OEM parts instead. So what are the key differences between OEM versus aftermarket parts? And when would you choose one over the other? Here we'll go over some pros and cons to help you balance cost and quality when it comes time for repairs.

Aftermarket parts

As noted, an aftermarket part is any part not sourced from the automaker. A 2022 study by AutomotiveResearch.com found that aftermarket parts accounted for about 50% of total parts purchases from independent repair shops. More than 30% of the 500 shops surveyed say they've increased aftermarket purchases in the last two years and plan to buy more in the next two years. Shops cite lower prices, more immediate availability, and quality that's equal to or better than the OEM part as their top three reasons for increasing their aftermarket parts purchases. These are the same reasons you too might consider aftermarket replacements.

Pros

• Less expensive: Aftermarket parts are usually less expensive than OEM parts, although how much you save varies by brand. Shop around to find the best price and to get an idea of how much that part usually costs. If the price of a part seems too good to be true, ask questions about its quality.

• Quality can be equal to or greater than OEM: In some cases, you may end up with a better part than you started with. The late Tom Torbjornsen, host of America's Car Show, told Edmunds that "the aftermarket companies reverse-engineer the part and work the weaknesses out." When an automaker designs its brake pads, for example, it needs to balance cost, durability, noise levels and performance. If you want better performance and don't mind some extra brake noise (some brake pads squeak even while stopping the car effectively), an aftermarket pad can be a good choice.

• More variety: Hundreds of companies make aftermarket parts. Some specialize in specific parts while others, like NAPA for example, make almost any part you can think of. More variety means greater selection and a wider range of prices.

• Better availability: You can walk into any gas station, auto parts store or local mechanic, and it'll probably have a part that fits your car. The broad accessibility gives you more options on where to take your car for service.

Cons

• Quality varies greatly: The saying "You get what you pay for" rings true here. Some aftermarket parts are inferior because they use lower-quality materials. Even if they don't affect the safety or operation of your car, they may simply wear faster and force a trip back to the garage sooner than expected. Stick with aftermarket brands you're familiar with or recommended by a mechanic you trust even if they cost more.

• Overwhelming selection: If you're not familiar with aftermarket brands, the selection could be overwhelming, and there's always a chance you get a bad quality part. Even a part as simple as a spark plug is made by dozens of different companies in numerous variations. Consult your mechanic for advice or simply stick with the OEM part when the price difference isn't significant.

• May not have a warranty: To reduce costs, some aftermarket parts are sold without a warranty.

OEM parts

OEM parts are made by the vehicle's manufacturer. These match the parts that came with your vehicle when it rolled off the assembly line.

Pros

• Easier to choose your part: If you go to the parts counter at a dealership and ask for any part, you'll usually get one type. You don't have to worry about assessing the quality of different brands and prices.

• Greater assurance of quality: The OEM part should work exactly as the one you are replacing. It was designed for your car specifically and offers peace of mind with its familiarity and performance.

• Comes with a warranty: Most automakers back their OEM parts with a one-year warranty. And if you get your car repaired at the dealer, they'll usually stand by their labor as well.

Cons

• More expensive: OEM parts usually cost more than an aftermarket part. That's especially true with bodywork, where OEM parts tend to cost about 50% more, according to the America Property Casualty Insurers Association. Parts (and service) can also carry a greater burden to help increase a dealership's profits, especially if sales departments are underperforming.

• Need to be bought at the dealership: There are other ways to buy OEM parts (eBay, online wholesalers), but most people will visit a dealership to buy their parts. This limits the number of places you can buy from. You can request OEM parts from your local independent mechanic, but they could take longer to arrive and delay your repair.

• Quality isn't necessarily superior: You paid the extra money for an OEM part, hoping that it was vastly better than an aftermarket part. But that may not always be the case. As Torbjornsen mentioned earlier, some aftermarket parts are equal to or in some cases better than OEM parts. You may just be paying extra for the name.

When should you request OEM parts?

When it comes to collision repairs, make sure you get OEM parts since aftermarket body panels may not fit properly or have proper crumple zones for crash safety.

If you lease your car, there are also economic considerations. Since aftermarket parts decrease a vehicle's book value, using them to repair your vehicle's body may cost you part or all of your security deposit.

There's a catch, though. In 21 states and the District of Columbia, a body shop's repair estimate doesn't need to indicate whether aftermarket parts will be used. And you'll often find that your insurance company favors aftermarket parts since they're cheaper. If you request OEM parts, some insurance companies ask you to pay an additional fee. Check with your insurance provider beforehand to see what parts they will cover.

Which is the best way to go?

All aftermarket parts are not created equal, but all OEM parts are. This creates its own set of advantages and disadvantages. If you're familiar with several brands or work on your own car, aftermarket parts can save you real money. If you're not familiar with aftermarket brands, or simply prefer to have work done by a dealer and don't mind paying more for potentially better quality and warranty support, then OEM is a fine choice.