How to Decide What’s Best for Your Car
If you’ve ever gotten your car repaired, you’ve probably wondered: What’s the difference between aftermarket parts, sold by third parties, and original manufacturer (also known as OEM) parts?
You can take your car to a dealer or an independent auto repair shop when it needs repairs. Dealers typically use OEM parts, while independent repair shops use aftermarket parts.
Both serve the same function, of course, but aside from that, they do differ in notable ways. Understanding these differences can help you make an informed decision when getting your car repaired.
What Are OEM Parts?
OEM car parts are made by the company that made your vehicle (OEM stands for Original Equipment Manufacturer). In many cases, these parts are identical to the parts your car had when the dealer sold it.
Unlike aftermarket car parts, OEM car parts typically don’t vary in quality. Whereas many different companies offer aftermarket car parts, OEM parts are typically made by just one company: the automaker that produced your car. Because these parts all come from the same source, they offer a consistent level of quality. Automakers will often refer to them as “Genuine Parts.”

What Are Aftermarket Parts?
An aftermarket car part is any part not made by the same company that makes your car. Aftermarket car parts are designed to be compatible with a wide range of makes and models.
Using aftermarket car parts can’t hurt your warranty coverage; the Federal Trade Commission (FTC), a consumer protection agency in the U.S., says that using aftermarket car parts will not void your vehicle warranty. That’s thanks to the Magnuson-Moss Warranty Act, which makes it illegal for automakers to deny warranty coverage or void your warranty simply because you used an aftermarket car part.
That changes, however, if the aftermarket part was defective or not correctly installed. If either of these scenarios damages another part covered under the warranty, a manufacturer or dealer has the right to deny coverage. According to FTC rules, the manufacturer or dealer must show proof that the aftermarket part triggered a need for repairs in order to refuse coverage.
That being the case, it’s important to be aware that the quality of aftermarket car parts can vary. It’s essential to ensure your mechanic uses high-quality aftermarket parts on your car.
OEM vs. Aftermarket: Advantages of Each
Advantages of OEM parts
Fewer choices to make: OEM car parts are made by the company that built your car. Typically, you’ll have just one option when purchasing an OEM car part, making it very easy to select a part for your vehicle.
Dependable quality: An OEM replacement part is often the exact same part that was in the vehicle when it rolled off the assembly line.
Warranty protection: Automakers typically back up their OEM parts with a warranty, which isn’t offered for aftermarket parts.
Advantages of aftermarket parts
More affordable: Aftermarket car parts are often less expensive than OEM parts, although prices – and quality – vary by brand. If a part seems unusually inexpensive, do your research to make sure you’re not sacrificing quality.
Availability: Many gas stations and auto repair shops use and sell aftermarket parts. This gives you a great deal of flexibility when servicing your vehicle. OEM car parts aren’t as widely available as aftermarket parts. Dealerships stock OEM parts, but independent repair shops usually have to order them, delaying the repair.
FAQs
What does OEM stand for?
OEM stands for “original equipment manufacturer,” meaning parts made by the same company that made your vehicle.
Where can I buy car parts?
OEM car parts are typically available from a car dealership. Independent repair shops usually won’t have OEM parts in stock, though they can order them. Aftermarket car parts are available at most auto repair shops.
Should I buy used car parts?
Buying used, refurbished, or recycled car parts can save you money. However, buying used parts adds complexity to your purchase since they are harder to find, and you need to consider the part’s age and condition. Both OEM and aftermarket car parts are available used. Junkyards, or salvage yards, are a common source of used car parts.
How many parts are in a car?
The average car has around 30,000 parts.