Studies keep confirming it: in-cabin air during traffic carries up to 10x more fine particles than the street outside — exhaust from the car ahead flows straight through your vents.
What helps
- Recirculation mode in tunnels and jams (short-term)
- Cabin filter replacement yearly (most people skip it)
- A true HEPA purifier — captures what the cabin filter misses: fine particles, pollen, smoke
What to look for
True HEPA (H13), sized to run continuously, quiet enough to forget. The Gearyx Pure fits the cup holder and runs on USB-C.