What Is the Difference Between OEM and Aftermarket Car Parts?

OEM vs aftermarket parts
OEM vs aftermarket parts

As your car ages, the parts that work together to keep it functioning may require replacement. When it’s time to replace your car parts, you can either purchase what you need from an authorized dealer (OEM parts) or get them from an independent shop that will usually supply ‘aftermarket’ parts.

The Distinction Between OEM and Aftermarket Parts

Authorized dealers sell OEM (original equipment manufacturer) parts, while independent repair shops mainly sell aftermarket parts. Although a mechanic can order OEM parts for you, they usually take a long time to arrive, thus leaving you carless for longer. So it’s important for you to know what’s best for you and your car. But first, what are the differences between OEM and aftermarket parts?

What You’re Getting

What is an OEM? An Original Equipment Manufacturer is a company that produces goods used as components for finished products. OEMs are directly linked to your car’s manufacturer. Therefore, their parts have specific designs and measurements to fit your car’s model and trim level. In a nutshell, OEM is all about staying true to the original parts. On the other hand, third-party companies manufacture aftermarket parts to resemble the original ones.


OEM parts can have a far superior quality compared to aftermarket ones. Since the parts come from your car’s manufacturer, you can be sure that they’ll perform exactly like the ones you’re replacing. There is no guesswork for OEM, and you are always sure of the safety and quality standards.

Aftermarket parts may not meet the manufacturer’s quality and safety standards. They might be made using cheaper, low-grade materials that will compromise your car’s safety and performance. Quality control is not a priority at all third-party manufacturers.


Longevity is another factor you should consider when buying replacement parts for your car. Since OEM parts involve using high-quality materials, they last longer than aftermarket parts. Additionally, genuine parts usually have a performance warranty. The manufacturer replaces the parts if they don’t perform as expected. Aftermarket parts are generally made of inferior materials that don’t last long, and their production process is less exacting.


Cheap parts are attractive, especially when you’re on a budget. However, they may cost you more as you struggle to maintain your vehicle’s performance down the road. Buying OEM parts may mean paying more upfront, but you’re sure the parts will last longer. Furthermore, you increase the operational life of your car. There is no risk of undue wear and tear that may arise from using parts that don’t fit your vehicle.


Any mechanic can successfully install an aftermarket part on your car, but that doesn’t mean the product will fit or perform as the original one. OEM parts guarantee compatibility in terms of dimensions and specifications. In addition, the original parts will work in harmony with the other components of your vehicle.

Cheaper cars are made to lesser standards so aftermarket parts can match their original quality. However higher-end vehicles, like BMWs, are manufactured to very high standards so by using BMW OEM parts for repairs you can be confident you are maintaining the quality and safety of your car. Not only this but these days cars are supercomputers with a myriad of arrays, sensors, and complex communication systems. It is essential that all parts in this network function properly and can communicate properly with the car’s computer. You can be confident OEM parts will do this, you can’t be confident aftermarket parts will.

You can buy some very high-quality aftermarket parts in some areas like shock absorbers, lights, and tires. These items can match and even surpass the original manufacturer in terms of their quality. However, you will find that these quality aftermarket brands are priced accordingly. You do in the end get what you pay for.

Final Remarks

The mechanics at your regular garage or insurance companies may recommend aftermarket parts for your car. Don’t fall into the trap. You may shave off a few cents, but remember: your car is a worthwhile investment that needs good care. Go for original parts from an accredited dealer to retain your baby’s value and performance for years to come.