PETG or ASA in a car? Choosing filament by mounting location

Which material for a gauge pod on the dashboard?

ASA (or ABS). After one hour in the sun a dashboard averages about 69 °C, with peaks up to 89 °C. ASA only softens at around 108 °C and is UV resistant. PETG is only fine in shaded spots like the air vent or centre console; PLA is unsuitable in a car.

Dashboard, 1 h sun
avg. about 69 °C, peak about 89 °C (ASU/UCSD study)
TCS measurement
77 °C
ASA softens
about 108 °C (glass transition, Stratasys)
PETG softens
about 80 °C
PLA softens
from about 55–60 °C

Why material matters in a car

A parked car gets very hot inside. According to a study by Arizona State University and UC San Diego, a dashboard reaches about 69 °C on average after one hour in the sun, with peaks up to 89 °C. The Swiss TCS measured 77 °C. A part that softens at these temperatures warps permanently – and the gauge ends up crooked or falls out.

Comparison

Material Softens at UV resistant Use in a car
ASA about 108 °C yes anywhere, required in the sun
ABS about 100 °C limited anywhere, yellows in the sun
PETG about 80 °C moderate shade only
PLA about 55–60 °C no unsuitable

Rule of thumb

Anything the sun hits directly is printed in ASA. Mounts in the shade are fine in PETG. PLA does not belong in a car.

Choosing the material for an interior part

  1. Identify the location: direct sun (top of dash, A-pillar, near the windscreen) or shade (vent, console, footwell).
  2. Sun: ASA or ABS. Shade: PETG or ASA.
  3. Never use PLA.
  4. Print the tolerance test ring in the chosen material and check the fit.

FAQ

Is PETG enough for an air-vent phone mount?

Yes. At the air vent and in the centre console the part sits in the shade; PETG is enough there. ASA is still the more robust choice.

Is ASA hard to print?

ASA needs a heated bed (about 100 °C), ideally an enclosure, and shrinks more than PETG. That is why every file includes a tolerance test ring.

Updated: 31 October 2026

Matching files