Car Parts

OEM vs. Aftermarket Parts: What Are The Differences & Which One Should You Buy?

As we strive to be responsible citizens and practice social distancing, we’ve pivoted to shopping exclusively online for many things we traditionally look for at brick-and-mortar stores. If you’re needing to tackle some DIY maintenance while staying home, or interested in upgrading some of your vehicle’s components, you will come across two types of parts while shopping online: original equipment manufacturer (OEM) and aftermarket.

Before you start browsing and filling your virtual cart, let’s tackle a few questions to better understand each type.

Difference Between OEM & Aftermarket Parts 

An OEM part is made by the same company that supplies the vehicle manufacturer’s factory. Historically, you could only get OEM parts through authorized dealerships. They were the go-to for everyday consumers as well as purists who wanted exact replacement parts for their vehicle. However, in recent years, OEM parts have become available through other retail stores and online via third-party sellers.

On the other hand, an aftermarket part is a component manufactured to appear and function just like the OEM part, but is made by a company competing with the OEM supplier. They’ve always been available at brick-and-mortar auto parts stores, but aftermarket parts rose in popularity because of e-commerce retailers.

Hobbyists flocked to online stores to explore alternative replacement parts, many of which offered unique and custom variations that weren’t available through the original manufacturer.

OEM vs. Aftermarket Parts

Are Aftermarket Parts Less Expensive?

Although not a hard and fast rule, in general, aftermarket parts are less expensive as most retailers strive to offer a competitive alternative. How much less expensive, though, will depend on the type of part and its availability. It’s not unusual to see different pricing tiers for aftermarket parts, based on value, so shoppers can easily browse for parts that are within their budget.

Pricing for aftermarket offerings will also vary depending on the retailer, with some retailers willing to offer discounts, and others adding larger markups. If you’re looking for a good deal, research is key.

Are Aftermarket Parts of Lower Quality?

Years ago, when the aftermarket first started to compete with OEM suppliers, some vendors may have compromised quality to be price-competitive. This was often done to win customers who were historically loyal to OEM suppliers.

Today, much of the aftermarket realizes the importance of quality, and you can find options from many sellers that are close competitors to their OEM counterparts. In fact, there are even some large aftermarket suppliers who have made it a selling point to state that their aftermarket components are superior to OEM ones, particularly if those OEM parts have known issues.

OEM vs. Aftermarket Parts

Is There a Risk of Counterfeit Parts? 

In this day and age, sadly, there is always that risk. Think about how there are knock-off watches, sunglasses, and handbags. Auto parts, unfortunately, fall into a similar situation. Airbags, brake pads, wheels, electrical components, and various other engine and drivetrain components are among the parts most commonly at risk.

The amount of counterfeit auto parts continues to rise, despite government and industry efforts worldwide to quell the activity.

How Do I Know It’s a Fake Part?

Keep an eye out for poor quality, misspellings, and wrong colors. When shopping online, look for listings that include several high-quality photos and detailed descriptions that include exact specifications.

One way to avoid counterfeit parts is by purchasing from reputable companies and re-sellers, preferably those that include reviews and have a dedicated customer service team available to you while you’re browsing.

OEM or Aftermarket Parts: Which One Is Best?

In some cases, there isn’t a choice! For newer cars, or for parts which are more expensive or in lower demand, OEM may be the only choice if the aftermarket has not yet offered any options. With an OEM part, you are also guaranteed an exact replacement of what was originally included on your vehicle, which will fit perfectly. For some purists, this is incredibly important and worth any cost discrepancy.

On the other hand, for obsolete brands or older vehicles, OEM support may have ended and the part you need might be hard to find. Dealers may now keep very few (if any) in stock, or the parts you need are scattered around the country, resulting in order and repair delays. In these instances, the aftermarket might provide you the parts you need more easily.

OEM vs. Aftermarket Parts

Best Practices When Shopping for Auto Parts

If a consumer does have a choice between OEM and aftermarket parts, the smart shopper makes a decision after looking at brand reputation, perceived quality, warranty, and availability, in addition to price. When shopping for car parts, you want to make sure you’ve done all your research and selected the right option that factors in budget, lifestyle, and safety.

The good news is, consumers and hobbyists alike have more options than ever for car parts, and they can all be accessed from the comfort of your own home. Between OEM and aftermarket parts, once you’ve weighed all the factors and your personal preferences, the choice is yours!

Richard Reina is the Product Training Director for, and Automoblog’s resident expert on the classic and collector car market. He enjoys restoring and driving old cars with a special love for anything Italian. Richard is also passionate about music and is a huge Beatles fan.

How to Get Invoice Pricing

  1. The topic of warranty protection when related to the “after market vs. O.E.M.” should include the The Magnuson-Moss Warranty Act. The short version and para-phrased version is something like: if a break-down or problem happens, the repair facility that attempts to void the warranty has to prove the the break-down was faulted by the after-market item. This is common with items like the engine lubricant and its filters.

  2. I like how you mentioned that parts are considered OEM because they’re manufactured in the vehicle company factory. My brother is thinking of looking for a valve timing system because he’s considering rebuilding a racing car in his garage to have as his daily driver. It seems like a good idea for my brother to think about buying auto parts from a reputable supplier so that his rebuilt car can operate as best as possible.

  3. A idiot kid without looking ran my escape titanium off the road onto the left curb ruining both left wheels. I’m paying a 2000 deductible for a crash not my fault. His jeep was covered in dried mud. I believe the aftermarket wheels liberty is trying to push on me by Marquis body shop through liberty is not satisfactory, wheels can break from hitting a pothole, and can crack the wheels or even make the wheels become out of round. Liberty is trying to pay the least expensive parts on even the broken tie rod under the front drive steering mechanism. Will I have to contain a lawsuit in order for them to fix the car correctly with OEM wheels instead of aftermarket wheels that are most likely lighter, the car will most likely not drive correctly with lighter wheels on left of car, and I am concerned about the integrity of the car, even the best sparkly blue paint. The aftermarket wheels on the left cannot be matched exactly as the wheels on the right side as the Escape Titanium. The aftermarket wheels will cost only 200 to 250 as compared to the original wheels costing much more manufactured by Ford. A $2000 deductible and Liberty is saying it will cost $2719 with deductible to fix tie rod, tires, and aftermarket wheels. I am requesting real Ford parts because I am not stupid! Your response please. Bill Proctor. 2114 N Elizabeth St. Pueblo Colorado 81003 817-521-7799.

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