The short answerASA for exterior. PETG for interior.
A car is hot, sunny, and rough on plastics. ASA is the pick for exterior parts that face sun and heat. PETG is the pick for interior parts. PLA fails in a car, because it softens near 60 °C.
What a car part asks of a filament
A car part faces sustained heat, UV, and vibration. The dashboard can reach 80 °C in the sun, and exterior parts face weather. The filament must hold shape and color in that heat. PLA and PLA+ both fail, because they soften near 60 °C.
How the materials compare
| Property | ASA | ABS | PETG |
|---|---|---|---|
| Heat resistance | High | High | Medium |
| UV resistance | High | Low | Low |
| Ease of print | Hard | Hard | Medium |
| Needs enclosure | Yes | Yes | No |
| Best for | Exterior parts | Interior parts | Interior parts |
When to pick ASA
Pick ASA for exterior car parts that see sun and heat. The Prusament ASA datasheet lists a heat deflection of 93 °C and UV resistance. ASA holds color and shape where ABS turns yellow and PLA warps.
When to pick PETG
Pick PETG for interior parts out of direct sun. It handles moderate warmth and prints without a heated chamber. For any part that faces direct sun or engine heat, use ASA.
Frequently asked
What is the best filament for car parts?
Can I print car parts in PLA?
ASA or ABS for car parts?
Is PETG good for car interior parts?
For the materials, read the ASA guide or PETG guide. For outdoor use, see which filament for outdoor use.
Related guides
Related
Sources & methodology
4 citations · reviewed 2026-07-09- 01Prusament ASA Technical Datasheetaccessed 2026-07-09Tier 1
- 02Polymaker PolyLite ABS Product Information Sheetaccessed 2026-07-09Tier 1
- 03Prusament PETG Technical Datasheetaccessed 2026-07-06Tier 1
- 04All3DP All 3D Printing Filament Types Explainedaccessed 2026-06-29Tier 2