Guide · Used-car paint inspection
How to spot a repainted panel
Compare adjacent panels and mirrored spots instead of judging one number. What DeFelsko and AUTO BILD advise, and why a thick reading is a lead, not proof.
Short answer
Look for a panel that reads clearly differently from its neighbors and from the same spot on the other side of the car. DeFelsko says a significant difference between adjacent panels strongly indicates repainting,[1] and AUTO BILD says a much higher reading on one side than at the mirrored spot indicates a repair with repaint.[2] Treat that as a strong lead, not proof: the gauge shows thickness, not the cause, and factories sometimes repaint too.
The two comparisons that work
Adjacent panels. Measure a door, then the fender and the next door, at matching positions. DeFelsko advises looking for consistent thickness around the car and measuring near seams about one inch from the edges.[1]
Mirrored spots. Measure the same spot on the left and right of the car: left front door center against right front door center, and so on. AUTO BILD recommends this side-to-side comparison.[2]
Both compare the car with itself, which avoids the problem that no single "normal" thickness exists. See normal car paint thickness.
Why a single number is not enough
The published "typical" figures disagree:
| Source | Factory figure | Higher figure it mentions |
|---|---|---|
| DeFelsko | Typically 100-180 µm; examples from about 75 to about 430 µm[3] | None given as a number |
| PPG Refinish (Australia/New Zealand) | About 90-120 µm[4] | Advises removing or sanding back refinish films of 300 µm or more; refinishing advice, not a test for repaint |
| AUTO BILD (2021) | Usually 80-150 µm[2] | Typically above 200 µm, as rough guidance only |
AUTO BILD itself warns that factories sometimes repaint and that its values are only rough guidance.[2] With DeFelsko reporting about 430 µm of factory paint on some SUV rocker panels,[3] a reading above 200 µm is not proof of a repaint on its own. The comparison on the same car tells you more than the number.
What a higher reading can be
- A repaint or partial refinish
- A factory repaint, which DeFelsko notes some vehicles have[3]
- Body filler under the paint: see can a paint gauge detect body filler
- A reading error from an edge, a curve or dirt: see readings that mislead
A panel that reads lower than the rest of the car is also a difference worth asking about. The gauge cannot tell any of these apart.
About app verdicts
Some gauge apps label panels for you. NexDiag's NexPTG app color-codes panels as factory, repaired or touched-up, or repainted or body filler using its SAPL system.[5] That is the maker's interpretation of the numbers. Treat it like your own comparison: a reason to look closer.
Experience matters
AUTO BILD says interpreting readings needs experience with vehicle generations and paint systems.[2] If a panel stands out and the purchase matters, ask the seller for the repair history and have a body shop or independent inspector look at it.
Next
Questions
How can you tell if a car has been repainted?
With a paint gauge, look for a panel that reads clearly differently from its neighbors and from the mirrored spot on the other side. DeFelsko and AUTO BILD both use these comparisons; a difference is a strong lead, not proof.[1][2]
How much thicker is a repainted panel?
No source we use gives a reliable number. AUTO BILD says manual repaints are typically above 200 µm but calls that rough guidance, and notes factories sometimes repaint.[2]
Can a factory paint job read thick?
Yes. DeFelsko reports about 430 µm on some SUV rocker panels and notes some vehicles are repainted at the factory.[3]
Should I trust a gauge app that says 'repainted'?
Treat it as a flag. NexDiag's NexPTG app color-codes panels with its SAPL system, which is the maker's interpretation of thickness readings, not proof of a repair.[5]