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Choosing between original equipment manufacturer, or OEM, and aftermarket car parts is all about squaring your priorities with your budget.
Each option has its benefits, but how long a part will last and its initial cost can vary widely depending on if you go with OEM or aftermarket parts. Which one you decide to go with will determine the impact on the overall cost of owning your car.
Here’s a comparison of the perks and drawbacks of OEM and aftermarket parts and which is the best option for certain situations.
What's the difference between OEM and aftermarket parts?
Let’s start with genuine parts, which are parts that were installed in your vehicle by the manufacturer when it was first sold. They often have the logo of the vehicle manufacturer, such as Honda or Subaru, printed on them.
Once you’ve purchased a vehicle and need to make repairs or replace parts for maintenance, the terminology changes to the following:
Original equipment manufacturer, or OEM. These parts are made by the same manufacturer that made the genuine parts in a car, but they’re installed when a car needs a repair. Because the same manufacturer makes OEM parts, they are guaranteed to fit in your car.
Some retailers use “genuine” to refer to OEM parts. This is a marketing tactic and doesn’t mean that the part will work better. A part is either an OEM part or not an OEM part — regardless of if it is described as “genuine.”
Aftermarket parts. These are made by manufacturers that did not make the original car parts and therefore do not qualify as OEM parts. They can often be used in place of OEM parts, but they carry the potential of not being fully compatible with your car.
Comparing OEM and aftermarket parts
There are benefits and downsides to OEM and aftermarket parts, and a quick comparison shows that OEM parts win for dependability as a longer-term investment. On the other hand, aftermarket parts offer more options and tend to be more affordable.
Here’s a quick comparison of their pros and cons.
Pros and cons of OEM parts
In general, OEM parts offer peace of mind, but that comes at a higher cost. Here are a few benefits and drawbacks to buying OEM parts.
Compatibility. OEM parts are manufactured to fit your vehicle and work like they’re supposed to with your car’s systems.
Longer life. Because they are made in the same way as genuine parts, OEM parts tend to be more reliable than aftermarket parts and last for longer.
Warranty. OEM parts should come with a warranty to protect you if the part is defective or doesn’t work properly. The specific warranty will differ by manufacturer.
Higher cost. Due to their better quality, OEM parts tend to cost more than aftermarket parts.
Limited availability. With a higher demand, OEM parts can have limited availability and take longer to order and get into stock.
Pros and cons of aftermarket parts
Aftermarket parts tend to go easier on your budget but don’t come with the guarantee that they’ll work for you.
More options. Aftermarket parts can be made by any company that wants to manufacture car parts, so you have more options when looking for a part.
Cheaper cost. Because there are more options available for aftermarket parts, they tend to be cheaper.
Inconsistent quality. Car manufacturers do not oversee the quality of aftermarket parts, so there's no guarantee that the part will work well or even fit your car correctly.
Limited warranty. Most aftermarket parts have limited warranties or no warranty at all, which means you’re out more money if the part is defective or doesn’t fit.
When to use OEM or aftermarket parts
Choosing between OEM and aftermarket parts might come down to what is the most important aspect for you and your budget.
If one of the scenarios below ranks at the top of your list, you’re likely to prefer one option over the other.
You have a warranty
If your vehicle is under warranty, using aftermarket parts could affect your warranty. As long as the aftermarket part works properly, your warranty will probably stay in effect. However, if the part causes an issue that then needs to be repaired, and a dealership can prove that the aftermarket part caused the problem, it could deny warranty coverage for that specific repair.
Consider: OEM parts.
You're on a tight budget
Car repairs can be a big hit to your auto budget. But avoiding a necessary repair is the worst option because it could cause more damage to your car and end up costing you more down the road. So if your budget can’t support the cost of an OEM part for a necessary repair, looking into aftermarket parts might be a better option.
Consider: Aftermarket parts.
You want the most time between replacing parts
Investing in car parts might be the way to go if you're looking to skip extra trips to the mechanic as much as possible. Choosing to install parts that have longer lifespans and tend to be more reliable can help you avoid the potential of more frequent part replacements in the future.
Consider: OEM parts.
You need a quick repair
If you need a repair performed immediately, you might need to consider availability more than anything else. Certain types of parts are more commonly kept in stock, but aftermarket options might be more readily available than OEM parts, depending on the auto shop’s inventory.
Consider: Aftermarket parts.
You want a guarantee that the part will work
Because manufacturers have different standards, not all parts will provide the same quality — and not all manufacturers offer a warranty for their parts. If the possibility of a newly-installed part failing within a year stresses you out, you’ll probably want to go with one that has a warranty in case it is faulty.
Consider: OEM parts.
Where to get parts
The options you’ll have for parts depend on the nature of the repairs and what type of shop you take your car to.
OEM parts are mostly easily available at dealership repair shops, while independent mechanics may be able to offer you a choice between OEM and aftermarket parts. Independent garages that specialize in your type of vehicle and auto body shops will likely be able to order both.
» MORE: How to handle a bad mechanic
If your repair is part of an insurance claim, the insurer might prefer aftermarket parts to save money. However, you have the option to pay the difference between the insurer’s preferred aftermarket part and the cost of an OEM part.
Depending on the job, the cost of OEM versus aftermarket parts varies. Whenever you’re given the choice, ask to see estimates for both so you can weigh your options.