Aftermarket parts are vehicle parts made by a company other than the vehicle’s original manufacturer. They are used both as replacement parts and as upgrade parts for performance, appearance, or functionality.
Quick Overview – TL;DR
- What does aftermarket parts mean? It means parts that are not made by the original vehicle manufacturer.
- Are aftermarket parts only for repairs? No. They can be used for repairs, maintenance, upgrades, styling, and performance modifications.
- Are aftermarket parts used parts? No. Standard aftermarket parts are generally new third-party parts. Used OEM parts are usually listed separately as recycled parts.
- Are aftermarket parts always worse than OEM? No. Quality varies by manufacturer and by part. Some are low-grade, while some are comparable to OEM.
- Do aftermarket parts automatically void a warranty? No. A manufacturer generally cannot void a warranty just because a third-party part was used.
What Does “Aftermarket Parts” Mean?
“Aftermarket parts” means parts sold for a vehicle after the original sale of that vehicle, usually by companies other than the automaker. In everyday use, the term refers to non-OEM replacement or upgrade parts.
A simple way to think about it:
- OEM part = made by or for the original vehicle manufacturer
- Aftermarket part = made by a third-party manufacturer
- Recycled part = used OEM part removed from another vehicle
- A/M certified part = new certified non-OEM replacement part
This distinction matters because many buyers use “aftermarket” as a catch-all term for anything non-OEM. That is not fully accurate. A used OEM part from a salvage vehicle is not the same thing as a newly manufactured aftermarket part.
What Are OEM Parts and What Does It Mean?
OEM stands for Original Equipment Manufacturer. OEM parts are parts made by the original vehicle manufacturer, or parts supplied to that manufacturer for the vehicle when it was built. In practice, OEM parts are the factory-standard replacement option.
When a repair estimate lists a part as OEM, it means the replacement part matches the original manufacturer source rather than coming from a third-party supplier. That is why OEM parts are often seen as the more predictable option for fit, finish, and brand-specific compatibility.
What Counts as an Aftermarket Part?
Aftermarket parts cover more than collision repair panels.
They can include:
- replacement parts such as bumpers, mirrors, lamps, radiators, and suspension components
- maintenance parts such as brake pads, spark plugs, belts, and batteries
- performance parts such as intakes, exhausts, intercoolers, and coilovers
- appearance parts such as grilles, spoilers, trim pieces, and interior accessories
That broader definition matters because “aftermarket parts” does not only mean crash repair. It also includes routine replacement, maintenance, restoration, and upgrade parts.
Aftermarket Parts vs OEM Parts
The core difference is who made the part, not what the part does.
| Factor | Aftermarket Parts | OEM Parts |
|---|---|---|
| Manufacturer | Third-party company | Original vehicle manufacturer |
| Purpose | Replacement, upgrade, or customization | Factory-equivalent replacement |
| Price | Often lower | Usually higher |
| Fit consistency | Varies by brand and tooling | Usually more predictable |
| Availability | Can be broad, especially for older models | Can be limited or expensive |
| Choice | Many brands and specs | Usually one official version |
Progressive defines aftermarket parts as parts not made by the original manufacturer, while OEM parts are identified as original equipment manufacturer parts on repair estimates.
Why Do People Buy Aftermarket Parts?
Most buyers choose aftermarket parts for one of four reasons.
Lower cost
Aftermarket parts are often cheaper than OEM parts. That is one reason insurers and repair shops frequently use them in estimates and repairs.
Better availability
For older vehicles, rare trims, or discontinued models, OEM stock may be expensive, delayed, or unavailable. In those cases, aftermarket suppliers can be the only realistic option. This is an inference based on the role aftermarket parts play as non-OEM replacements across repair markets.
More choice
OEM usually gives the buyer one factory option. Aftermarket gives multiple brands, quality tiers, and specifications. That matters when the buyer wants either a lower-cost replacement or a different performance level.
Customization
Some aftermarket parts are purchased not because the original broke, but because the owner wants a different look or function. Progressive treats non-factory enhancements as modifications, which fits the broader aftermarket category.
Are Aftermarket Parts Good Quality?
Sometimes yes. Sometimes no.
That is the honest answer.
The category is too broad to judge as a whole. Quality depends on the manufacturer, the tooling, the material, and the exact part. Progressive explicitly notes that aftermarket part quality depends on the manufacturer.
One useful quality signal is CAPA certification in collision-related replacement parts. CAPA states that its quality seal appears only on replacement parts that meet or exceed CAPA standards and that the seal is proof the part is certified to fit, perform, and last like the original.
That does not mean every good aftermarket part is CAPA-certified, or that CAPA applies to every part category. It means buyers should judge aftermarket parts by supplier reputation, certification where relevant, fitment accuracy, and application.
Are Aftermarket Parts Legal?
Generally, yes.
NHTSA states that it has not issued regulations restricting the use of aftermarket parts in vehicle repairs, except in certain safety-related contexts. NHTSA also says the use of an aftermarket part is permitted by federal law as long as the repair shop does not knowingly make inoperative a required safety system.
This means two things are true at the same time:
- aftermarket parts are commonly used and generally lawful
- safety-related systems still need to remain compliant and functional after repair
Do Aftermarket Parts Void Your Warranty?
Not automatically.
The FTC has repeatedly warned companies not to condition warranty coverage on the use of branded parts or authorized repair services unless a narrow legal exception applies. FTC materials also state that using third-party parts cannot automatically void warranty coverage.
The practical version is simple:
- Using an aftermarket part alone does not automatically void the warranty
- Using a bad or incorrect aftermarket part can still create a warranty dispute if that part caused the problem
The second point is a practical inference from how warranty causation works, while the first point is directly supported by FTC guidance.
When Aftermarket Parts Make Sense
Aftermarket parts usually make sense when:
- the OEM part is overpriced for the age or value of the vehicle
- the OEM part is discontinued or hard to source
- the buyer wants multiple options instead of one factory choice
- the supplier can show strong fitment confidence or certification
- the vehicle owner wants to upgrade rather than simply restore
This conclusion follows from the cost, modification, and replacement role described in the cited sources.
When OEM May Be the Better Choice
OEM may be the better choice when:
- the part interacts with critical safety systems
- calibration, sensor placement, or tight tolerances matter
- the repair needs exact factory-match compatibility
- resale perception matters to the owner
- the customer wants the most predictable manufacturer-source replacement
NHTSA’s guidance on not making safety systems inoperative supports a more cautious approach for highly integrated or safety-sensitive repairs.
Common Misunderstandings About Aftermarket Parts
“Aftermarket means fake”
Wrong. Aftermarket means non-OEM. It does not automatically mean counterfeit, low-quality, or used.
“Aftermarket parts are always cheaper because they are worse”
Not always. They are often cheaper because they come from competing manufacturers, but quality varies by supplier and by product.
“Aftermarket parts are only for modifications”
Wrong. Many are direct replacement parts used in normal repairs and maintenance.
“Using aftermarket parts voids the warranty”
Not by itself. FTC guidance is clear on that point.
FAQ
What are aftermarket parts?
Aftermarket parts are vehicle parts made by a third-party manufacturer rather than the original vehicle manufacturer. They can be used for repairs, maintenance, upgrades, or cosmetic changes.
What does aftermarket parts mean?
“Aftermarket parts” means parts sold for a vehicle after the original sale of the vehicle, usually by companies other than the automaker. In normal use, it refers to non-OEM replacement or upgrade parts.
What are OEM parts?
OEM parts are parts made by the original vehicle manufacturer, or by a supplier for that manufacturer, to match the factory-standard part source.
Are aftermarket parts the same as used parts?
No. Standard aftermarket parts are generally new third-party parts. Used parts are usually recycled OEM parts taken from another vehicle.
Are aftermarket parts cheaper than OEM?
Often yes, but not always. They are commonly used because they are often lower-cost alternatives to OEM parts.
Are aftermarket parts safe?
They can be, but the answer depends on the exact part and manufacturer. Some aftermarket equipment is subject to federal safety standards, and repair businesses cannot knowingly compromise required safety systems.
Do aftermarket parts void a factory warranty?
Not automatically. FTC guidance says warranty coverage cannot simply be tied to branded parts or authorized repair services in the usual way many companies imply.
What is a CAPA-certified part?
A CAPA-certified part is an aftermarket replacement part that carries CAPA’s quality seal, indicating it met CAPA standards for fit, performance, and durability.
Final Conclusion
Aftermarket parts are non-OEM vehicle parts made by third-party manufacturers. OEM parts are original manufacturer parts tied to the vehicle’s factory source.
That is the clean distinction.
In practice, aftermarket parts include low-cost replacements, certified repair parts, hard-to-source components, maintenance items, and performance upgrades. Some are excellent. Some are mediocre. The right question is not “OEM or aftermarket?” as a blanket rule. The right question is:
Which supplier, which part, for which exact application?
This article is written by NeoGrade team.
NeoGrade restores access to discontinued and hard-to-source parts for older vehicles, legacy machinery, and specialist equipment.
We help keep valuable machines in service by stocking selected high-demand parts and recreating unavailable components through reverse engineering, CAD reconstruction, and modern manufacturing.
Based in Estonia and serving customers worldwide, NeoGrade helps reduce repair delays, downtime, and sourcing dead ends.
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