Guide · Used-car paint inspection
Normal car paint thickness
DeFelsko, PPG and AUTO BILD publish different typical paint thicknesses. The figures side by side, why they differ, and what to compare against instead.
Short answer
There is no single normal number. DeFelsko says there is no absolute "right" paint thickness, though factory paint typically falls between 100 and 180 µm.[1] PPG's Australia and New Zealand refinish guide gives about 90-120 µm,[2] and AUTO BILD gives 80-150 µm as rough guidance.[3] The ranges differ, so compare panels on the same car rather than against any one figure.
The published ranges, side by side
| Source | Figure | What it is |
|---|---|---|
| DeFelsko | Factory paint typically 100-180 µm[1] | A gauge maker's "typical" range |
| DeFelsko | About 75 µm on some roofs; about 430 µm on some SUV rocker panels[1] | Examples of how far factory paint can vary |
| PPG Refinish (Australia/New Zealand) | Approximate OEM finish 90-120 µm[2] | One regional refinish example |
| AUTO BILD (2021) | Factory finishes usually 80-150 µm; manual repaints typically above 200 µm[3] | Rough guidance for its market, in its own words |
None of these is a pass/fail line. They come from different markets, eras and purposes, and they do not agree.
Why the numbers vary
- Different panels. DeFelsko's own examples run from about 75 µm on a roof to about 430 µm on SUV rocker panels.[1]
- Factory repaints. DeFelsko notes some vehicles are repainted at the factory,[1] and AUTO BILD warns the same.[3]
- The whole stack. A gauge reading on metal includes primer, color, clear coat and anything else on top.[1]
- The gauge. Every reading carries the gauge's own error; see accuracy vs resolution.
What to compare against instead
The most useful reference is the same car. Measure every panel, then look for a panel that stands out from its neighbors and from the same spot on the other side. See how to check a used car's paint.
Microns and mils
One mil is one thousandth of an inch, 25.4 µm; a micron is one thousandth of a millimeter.[1]
| Microns | Mils (approx.) |
|---|---|
| 75 µm | 3.0 |
| 100 µm | 3.9 |
| 127 µm | 5.0 |
| 180 µm | 7.1 |
| 200 µm | 7.9 |
| 300 µm | 11.8 |
Clear coat is a separate question
DeFelsko gives typical clear coat as 35-50 µm, but that is its rough figure, not a carmaker specification, and a standard paint gauge cannot isolate the clear layer anyway.[1] See can a paint gauge measure clear coat.
Next
Questions
Does 200 microns mean a panel was repainted?
No source we use sets that threshold. AUTO BILD says manual repaints are typically above 200 µm but calls its figures only rough guidance, and DeFelsko reports about 430 µm of factory paint on some SUV rocker panels.[3][1]
What does a 300 µm reading mean?
Only that the coating on that spot is thicker than DeFelsko's typical factory range. PPG's 300 µm figure is advice to remove or sand back refinish films that thick, not a test for repaint.[2][1]
What about 500 µm or more?
No source we use gives a meaning for a specific number. In one DeFelsko case study a panel read 930 µm and turned out to be plastic filler over a rust repair, but that was one vehicle.[4]
Can factory paint be uneven?
Yes. DeFelsko gives examples from about 75 µm on some roofs to about 430 µm on some SUV rocker panels, and notes some vehicles are repainted at the factory.[1]
How many mils is normal paint?
Divide microns by 25.4. DeFelsko's typical 100-180 µm is about 3.9-7.1 mils.[1]