ASA vs ABS vs ABS-GF: Which Material for Car Parts?

For parts that live in the sun, such as car vents, ASA is generally a better choice than ABS, because ABS is known to yellow and turn brittle under UV. For parts behind the windscreen that need to stay stiff, we print in ABS-GF, which is glass fibre reinforced ABS. For small items that sit in a hot car, like keychains, plain ABS does the job. Here is which material we use where, and why.

What is the difference between ASA and ABS?

ABS (acrylonitrile butadiene styrene) is a tough, widely used engineering plastic. ASA (acrylonitrile styrene acrylate) is a close relative that was developed to fix ABS's main weakness: sunlight.

Two filament makers we checked make the same point. One says plainly that UV exposure breaks ABS down, and that an ABS part can show visible yellowing after a few months outside. The other says ABS is prone to fading and brittleness in sunlight, while ASA has enhanced UV resistance and holds up better outdoors.

Both also say ASA tends to be easier to print than ABS, with less warping. That matters for a workshop printing larger flat parts, because warping is the enemy of a good fit.

• ABS: tough and impact resistant, but it degrades in sustained UV.
• ASA: similar strength, with much better UV and weather resistance.
• ABS-GF: ABS with glass fibre added, which makes it stiffer and more heat resistant than plain ABS.

Why do we print the Hilux vents and cup holder in ASA?

Early Hilux interiors take a hammering from the Australian sun. Windows, vents and anything near the glass cop direct UV for hours a day, which is exactly where ABS struggles and ASA is meant to cope.

So our vents are printed in ASA. The B-pillar cab vent louver pair and the internal vent pair are both listed as ASA, chosen for strength, UV resistance and long-term durability. They are made to snap in place of cracked, sun-damaged factory originals.

The same goes for the cup holder conversion for the 1979-1983 RN/LN Hilux, which is printed in ASA and slides into the spot where the factory ashtray sits. If you want the full story on that one, we wrote it up in Adding a cup holder to a 1979-1983 Hilux, no drilling.

What is ABS-GF, and why are the dash faces made from it?

ABS-GF is ABS reinforced with glass fibre. According to our product pages, the glass fibre makes it stiffer and more heat resistant than plain ABS, so a part stays rigid and holds its shape in a hot cab. That is the job of a dash face, which sits behind the windscreen all day.

Our dash faces and the 1983-1988 cup holder conversion are printed in ABS-GF. It has a textured matte finish straight off the printer, and the dash faces can be sanded and painted if you want to colour-match your interior.

The dash faces and vents are aftermarket reproductions, not genuine Toyota parts, and are not made or endorsed by Toyota. OEM numbers on our product pages are for reference only. Always confirm fitment before purchasing.

Where do we use plain ABS?

Plain ABS suits small items that need to cope with heat and knocks. Our Audi, BMW and Mercedes keychains are printed in ABS, and the Formula 1 style tyre plant pot is ABS too.

The reason is heat. Our product pages note that, unlike standard 3D printed accessories, ABS is impact resistant and handles the heat of a car interior without warping, which is why we use it for things like the Audi enthusiasts keychain.

Is ASA perfectly UV proof?

No. It is much better than ABS in sunlight, but no plastic lasts forever outdoors, so do not expect any material to be maintenance free.

Most of what is published about filament comes from filament sellers, so treat comparisons as a guide. For vents that take plenty of sun, ASA is a sensible choice, and that is why we use it.

Questions we get asked

Can I print car parts in PLA?

We do not make our car parts from PLA. Our keychain and planter pages explain that we use ABS instead of the PLA common in standard 3D printed decor, because ABS handles the heat inside a car without warping.

Why not print everything in ASA?

Different parts need different things. A dash face needs stiffness and heat resistance behind the windscreen, which is where glass fibre reinforced ABS comes in. A vent needs to shrug off sunlight, which is where ASA comes in.

Can I paint a dash face?

Yes. Our dash face pages say the ABS-GF can be sanded and painted if you want to match your interior.

Will the parts fit my truck?

Check the fitment listed on each product page and compare the photos with your original part before purchasing. If you are unsure, get in touch first.

Looking for a part we do not make yet? Send us the details through our custom request page, or have a look at all our Hilux parts.