“Used” covers a huge range of actual condition, from a part pulled off a car with 20,000 miles on it to one that’s been in service for a decade. The industry’s answer to that ambiguity is a grading system, and understanding how it works is the fastest way to know exactly what you’re getting before you buy.
This guide covers the industry-standard A/B/C grading system, how mechanical and body parts are graded differently, and what our own inspection and warranty process looks like.
The A/B/C Grading System
| Grade | Mechanical Parts (Mileage-Based) | Body Parts (Damage-Based) |
|---|---|---|
| A | Typically under 60,000 miles, or under roughly 15,000 miles per year | No damage, or the equivalent of one minor repair unit |
| B | Typically under 200,000 miles total | Moderate damage or wear, still fully functional |
| C | Typically 200,000+ miles | More than moderate damage, priced accordingly |
Where This System Comes From
The A/B/C grading framework was developed by the Automotive Recyclers Association (ARA), the industry’s leading trade organization, in partnership with CIECA, an international body focused on standardizing collision repair estimating and parts data. It gives buyers, insurers, and collision repair shops a common language for describing used part condition instead of relying on a seller’s subjective description alone.
ARA also backs the CAR (Certified Automotive Recyclers) program, administered with support from NSF International, which certifies recycling facilities on business practices, safety, and specifically on grading and labeling accuracy — a seal of legitimacy beyond just following the grading terminology.
Mechanical vs. Body Parts: Different Grading Logic
Mechanical parts like engines, transmissions, and alternators are graded primarily by mileage and average annual use, since these are reasonable proxies for internal wear even before a part is tested. Body parts are graded by visible damage instead, since a fender’s condition has nothing to do with the donor vehicle’s odometer. This is why a single donor vehicle can supply parts across multiple grades: a car totaled at 40,000 miles might yield an A-grade engine and transmission, alongside a C-grade fender that took the brunt of the collision.
Why Grading Exists in the First Place
Before a standardized system, buyers had almost no way to compare a used part’s condition across different sellers other than trusting each seller’s own description, which varied wildly in how honestly and consistently it was applied. Collision repair shops and insurers, who buy in volume and need to estimate repair costs accurately, pushed for a common standard specifically so an “A-grade fender” from one recycler meant roughly the same thing as an “A-grade fender” from another. That standardization is also what makes it possible for estimating software used across the collision repair industry to price used parts consistently into repair estimates, rather than treating every used part quote as a one-off negotiation.
Grading Is a Starting Point, Not the Whole Picture
- Grade reflects likely condition based on mileage or visible damage, but it isn’t a substitute for actual testing on functional parts like engines, transmissions, and electrical components.
- Ask whether a mechanical part’s grade was confirmed with an actual function test (compression test, bench test, pressure test) or assigned by mileage and visual inspection alone.
- A warranty backed by real testing is a stronger signal of quality than the grade letter by itself, regardless of how the part is labeled.
- Price should track grade consistently — if a “Grade A” part is priced like a Grade C part, ask why.
What Actual Testing Looks Like by Part Type
| Part Type | How It’s Tested | What It Confirms |
|---|---|---|
| Engine | Compression test, visual inspection for leaks or damage | Cylinder health, absence of major internal issues |
| Transmission | Fluid condition check, shift behavior if run on a stand | No slipping, no contamination, proper operation |
| Alternator / starter | Bench test under electrical load | Correct voltage output or cranking performance |
| Body panels | Visual inspection, fitment check against reference specs | No hidden damage, correct mounting points |
This is the layer that matters most once you’ve confirmed a part’s grade: two Grade B engines can have very different levels of confidence behind them depending on whether one was actually compression-tested and the other was just mileage-checked and eyeballed.
How We Handle Grading and Testing
Every part we sell is inspected against these same industry standards, but grade alone never determines whether something goes on our shelves. Mechanical parts are function-tested, not just mileage-checked, and every part, regardless of grade, is backed by a warranty covering defects found after installation. We’d rather tell you a part is Grade B and function-tested than call it Grade A on mileage alone with no verification behind it.
How Grade Affects Price
Grade and price should move together in a predictable way: a Grade A engine commands a premium over a Grade B or C example of the same part, reflecting the lower risk of near-term issues from age or wear. This isn’t just about being fair to the buyer, either, since a seller who consistently overprices lower-grade parts by mislabeling them erodes the trust that makes the whole grading system useful in the first place. When you’re comparing quotes from different sellers, ask each one to state the grade explicitly rather than just quoting a price, so you’re comparing like for like.
Where Englewood Used Auto Parts Fits In
Browse our used auto parts inventory or call ahead with your VIN to confirm current availability and condition grade.
Not sure how to confirm your VIN before ordering? Our VIN and vehicle compatibility guide covers exactly what to check. And if you’re comparing us against a self-service option, our junkyard vs. used auto parts store guide explains the tradeoffs. If you’re leaning toward pulling a part yourself, our DIY part removal guide covers the tools and safety steps involved. Since grading also accounts for corrosion, our rust and used parts guide covers what to check on any part before you buy. And if you’re wondering how much life a graded part actually has left, our used parts lifespan guide covers that question directly.
Frequently Asked Questions
What does Grade A mean for a used part?
For mechanical parts, it generally means low mileage, typically under 60,000 miles or under about 15,000 miles per year. For body parts, it means minimal to no damage. Either way, it’s a starting point, and actual testing matters more for functional components.
Who created the A/B/C used parts grading system?
The Automotive Recyclers Association (ARA), the leading trade organization for the auto recycling industry, developed the standard in partnership with CIECA, an international collision repair estimating standards body.
Is a Grade B part reliable?
Yes. Grade B simply reflects moderate mileage or wear rather than damage, and a properly tested Grade B part is a reliable, more affordable alternative to Grade A for most repairs.
Does grade replace the need for a warranty?
No. Grade describes likely condition based on mileage or damage; a warranty backed by actual testing is a stronger indicator of a part’s reliability than the grade letter alone.
Do you grade parts before or after testing?
Both matter to us: a part’s grade reflects its mileage or condition, but mechanical parts are also function-tested before being cataloged, and every part is backed by a warranty regardless of grade.
What testing confirms an engine is actually good, not just low mileage?
A compression test checks cylinder health directly, along with a visual inspection for leaks, coolant contamination, or other damage. Mileage alone tells you the grade; testing tells you whether that grade is actually backed up.
Have an old vehicle you’re thinking of selling rather than repairing? Our guide to selling a junk car for cash covers what it’s actually worth.
Have a question about a specific part’s grade or testing history? Contact our parts counter and we’ll walk you through exactly what was checked.
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