In short. Neither type is better in general. The pad makers and motoring sources we read agree that ceramic pads are quieter and leave lighter, less visible dust, and that semi-metallic pads bite harder, especially from cold, and suit heavy loads and repeated hard braking; the two that discuss pad life say ceramic lasts longer, without figures, and they contradict each other on heat. The first rule is the type your car was built with: in Europe and the UK a replacement pad must carry an approval to UN Regulation 90, which compares it with the original pad, not with a material. A ceramic pad is not a carbon-ceramic brake: that is a disc, made by Porsche, Brembo and others, with its own pads.
Three different things called "ceramic"
Most confusion starts with the word. Three products on a car share it, and they have nothing to do with each other.
| Name | What it is | Where it sits | What it changes |
|---|---|---|---|
| Ceramic brake pad | A friction material (the lining glued to the pad's steel backing plate) made with ceramic compounds and fibres | Inside the caliper, against an ordinary cast-iron disc | Noise, dust colour and quantity, bite, disc wear |
| Carbon-ceramic brake (Porsche PCCB, Brembo CCM) | A disc made of a ceramic composite reinforced with carbon fibre, sold with matching pads | The disc itself, usually with larger calipers | Weight: Porsche and Brembo both give 50 per cent lighter than cast iron |
| Ceramic coating | A liquid that cures into a hard film on paint or metal | On the wheel or the bodywork | How easily dust washes off; nothing to do with braking |
Sources: Porsche, original brakes; Brembo, carbon ceramic; our guide to ceramic coatings for wheels.
Ceramic pads do not make a car's brakes carbon-ceramic, and carbon-ceramic discs take their own pads: Brembo lists its CCM disc with "carbon ceramic pads". The rest of this guide is about pads on cast-iron discs.
What each pad is made of
A pad is a steel backing plate with a block of friction material on it. The material is a mix of fibres, fillers, friction modifiers and a resin binder, and each maker keeps its recipe to itself. The families are named after what dominates the mix.
- Organic, or NAO (non-asbestos organic). Rubber, carbon, glass or fibreglass and other materials bound with resin, according to an ADVICS product manager writing in Vehicle Service Pros (6 July 2022). Soft, quiet, for light everyday use.
- Semi-metallic. Between 30 and 70 per cent metal, such as copper, iron and steel, with graphite as a lubricant and fillers (same source; AAA gives the same range).
- Low-metallic ("low-met"). A smaller share of metal than a semi-metallic pad. Akebono sells its ceramic pads for European cars as "the ultimate upgrade for semi-metallic and low-metallic brake pads" (Akebono EURO), which suggests, in our reading, that it expects to find those types on such cars.
- Ceramic. A dense ceramic compound, sometimes reinforced with other materials for friction and heat; ADVICS notes that pads made before 2015 often contained copper fibres.
Two things blur these labels. "Ceramic" is not a defined grade: no standard we read says how much ceramic a pad must contain. And copper is leaving the recipes because of the US laws below; Akebono says it went copper-free while avoiding "reintroducing ferrous metal" (Akebono, low copper), which suggests, in our reading, that iron is the easy substitute. Two pads with the same label can behave quite differently.
The comparison, with sources
This is what the sources we read say. None publishes an independent test that compares the two families on the same car, so read the table as a summary of claims, not of measurements.
| Criterion | Ceramic | Semi-metallic | Agreement between sources |
|---|---|---|---|
| Noise | Quieter; AAA says "virtually silent" in normal braking | Noisier: squeal or grinding | All agree |
| Dust | Finer and lighter in colour, less visible on wheels | Dark and gritty, dirties wheels quickly | All agree |
| Bite from cold, wet | Less initial bite | Stronger initial grip in cold or wet (AAA) | Broad agreement |
| Heavy loads, towing, repeated hard stops | AAA: may lose some power in continuous hard braking | Preferred for towing, track and performance use | Agree on use; disagree on heat (next row) |
| Temperature range | ADVICS: consistent "across a wider range of temperatures" and quick recovery | ADVICS: brake well across a wider temperature range and conduct heat away | The same article says both; the claim is unresolved |
| Disc (rotor) wear | Less abrasive, discs last longer | More abrasive, can shorten disc life | Agree, no figures |
| Pad life | ADVICS and AAA: ceramic usually lasts longer | No figure in any source we read | Two sources, no figures |
| Purchase price | Usually higher | Usually lower | Agree, no figures |
Sources: ADVICS in Vehicle Service Pros; AAA; Akebono EURO. This table is our own reading of those pages, made on 16 October 2026.
Akebono publishes wear and noise charts for its EURO pads, but against competitors it does not name, under conditions it does not describe; we do not reproduce them.
Dusty wheels on European cars: what the pad makers say
Owners of German cars often ask why their front wheels turn grey so quickly. The pad makers' own catalogues give the outline of an answer, without a figure. Akebono sells its EURO ceramic line as an upgrade for the semi-metallic and low-metallic pads it expects on European cars, says it uses "specific formulations for European vehicles", and claims it "virtually eliminates] brake dust" and lengthens disc life ([Akebono EURO). Brembo, whose standard Xtra pads carry ECE R90 approval, lists a separate Xtra Ceramic version for "top end vehicles", with "clean rims" among its claims (Brembo, Xtra). In other words, the clean-wheel pad for these cars is sold as an aftermarket option. We found no car maker's document explaining why its own choice is dustier. Bosch takes the opposite approach for its QuietCast range: it offers platform-specific ceramic, semi-metallic and NAO formulations and, in its own words, matches the type originally installed: "If the vehicle manufacturer installed ceramic, Bosch replaces with ceramic" (FenderBender, 1 January 2020). Two pad makers, two approaches; moving away from the original type is the owner's choice.
What the rules say, country by country
UK and European Union: UN Regulation 90
UN Regulation 90 covers replacement pads for cars and vans. The EU applies it to the sale of new replacement pads for cars (category M1) and vans (N1) whose vehicle type received EU approval on or after 7 April 1998, from 1 November 2014 (Regulation (EU) 2015/166, Article 7). We read it on legislation.gov.uk, which publishes EU-derived law as it applies in Great Britain; we did not check later British amendments. The pads fitted by the car maker, and the car maker's own replacement pads, are outside it (paragraph 1.2).
The regulation does not mention ceramic or metallic. Its paragraph 5 sets general requirements, among them that "a replacement part shall display performance characteristics similar to that of the original part it is intended to replace" and that "brake linings shall not contain asbestos". For cars, Annex 3 then compares the replacement pad with the original on a test vehicle. In the cold performance test, the replacement is accepted if its decelerations at the same pedal force or line pressure, in the upper two thirds of the curve, are "within 15 per cent of those obtained with the original brake lining assembly" (Annex 3, 2.1.1.3). In the speed sensitivity test, the decelerations from higher speeds must lie within 15 per cent of the one from the lowest speed (2.1.2.3). Pads are sold in axle sets, in a sealed package listing the vehicles the approval covers, and each pad carries the approval mark and the month and year of manufacture, or a batch number (6.1).
These quotations come from a consolidated documentation copy of the regulation, current to 2017 (R90 consolidated); the latest supplement we found came into force on 5 June 2023 (Amendment 10). The UN's own server refused our request, so check the authentic text before relying on a detail.
What 15 per cent means on the road: our calculation. Take a reference deceleration of 5 m/s², the figure Annex 3 uses for front brakes. A 15 per cent window around it runs from 4.25 to 5.75 m/s². With d = v² / 2a, the braking distance alone (no reaction time) from 100 km/h (27.78 m/s) is:
| Deceleration at the same pedal pressure | From 100 km/h | From 60 mph |
|---|---|---|
| 4.25 m/s² (15 per cent below) | 90.8 m | 278 ft |
| 5.00 m/s² (reference) | 77.2 m | 236 ft |
| 5.75 m/s² (15 per cent above) | 67.1 m | 205 ft |
This is arithmetic at equal pedal pressure, not a measurement: in an emergency stop the driver presses harder and the tyres and ABS set the limit. It shows that a pad that passes R90 can feel noticeably different from the original, in either direction.
The MOT. The inspection manual does not look at the pad material. It records a pad or lining worn down to the wear indicator as major, worn below 1.5 mm as dangerous, contaminated with oil or grease as major, and missing or incorrectly mounted as dangerous; a disc significantly and obviously worn is major (MOT inspection manual, 1.1.13 and 1.1.14).
United States: no approval, but a copper law and an edge code
FMVSS No. 135 "applies to passenger cars manufactured on or after September 1, 2000" and to some light trucks and buses (49 CFR 571.135). It sets the braking performance of new vehicles; the sections we read do not regulate replacement pads, and we found no federal approval scheme like R90.
What pads sold in the US do face is copper. Washington State's Better Brakes Law limits asbestos, hexavalent chromium, mercury, cadmium and lead to 0.1 per cent by weight from 2015, and copper to under 5 per cent from 2021 and under 0.5 per cent from 1 January 2025 (Washington Ecology). California has a similar law, and a voluntary agreement signed on 21 January 2015 by the EPA, the states' environmental council and industry groups extends the same targets nationwide (EPA, archived page). The reason is water: the EPA says copper from stormwater runoff "can affect fish, amphibians, invertebrates, and plants". The box shows the result as a LeafMark: one leaf (A) for the heavy metals, two (B) for under 5 per cent copper, three (N) for all the 2025 requirements.
The two letters marked on many pads are a friction classification under SAE J866, based on the SAE J661 brake lining quality test, a laboratory procedure. SAE itself warns that the document "does not establish friction requirements" and that its codes "cannot reliably be used to predict brake system performance" (SAE J866, stabilised March 2019). The code is useful for one thing: comparing a replacement pad with the original. It says nothing about noise, dust or the word "ceramic".
Canada
Canada's standard for new light vehicles, Technical Standards Document No. 135, reproduces FMVSS 135; Revision 5 was published on 1 May 2026 and is mandatory from 1 November 2026 (Transport Canada). We found no Canadian approval scheme for replacement pads and no Canadian copper rule in the documents we read; some ranges cover both countries (Bosch announced its QuietCast range for the United States and Canada, FenderBender), but we did not verify their labelling.
Australia
Brake rules for new vehicles are set by the Australian Design Rules; we did not read ADR 31 itself and found no national approval scheme for replacement pads. The NSW brake assessment manual (2017) applies to modified vehicles and for its pedal-travel check, treats a bonded lining as fully worn within 0.8 mm of the backing plate, or at the limit the manufacturer recommends; it is not a general replacement threshold (Transport for NSW). If your car has modified brakes, ask an engineer licensed under your state's vehicle modification scheme.
Brake dust is becoming a regulated emission
Euro 7, Regulation (EU) 2024/1257, adds a limit on brake particles for the first time. The European Parliament's summary of the agreed text gives 3 mg/km for pure electric cars and 7 mg/km for other powertrains, and 5 and 11 mg/km for heavy vans (European Parliament, 13 March 2024). The UK Department for Transport lists the Euro 7 dates as 29 November 2026 for new light vehicle types and 29 November 2027 for all new light vehicles (explanatory memorandum, 2 September 2026).
Our arithmetic, assuming 15,000 km a year: 7 mg/km is at most 105 g of brake particles a year, and 3 mg/km is 45 g. We did not find in the texts we read how the limit will treat replacement pads fitted later. Lower-dust discs already exist: Porsche offers a cast-iron disc with a ceramic coating, PSCB, with "significantly reduced formation of brake dust" (Porsche).
Carbon-ceramic brakes: a different decision
Porsche introduced its PCCB in 2001 on the 911 Turbo and 911 GT2, and says the ceramic discs are "50 percent lighter than gray cast-iron discs with comparable braking power" (Porsche Newsroom, 2 July 2015). Brembo gives the same 50 per cent for its CCM disc and an approximate life of 150,000 km on the road against 2,000 km in extreme track use (Brembo). The weight saved is unsprung mass, which our guide to lightweight wheels and unsprung weight explains.
The pads on these discs are specified with the disc. Do not fit an ordinary ceramic or semi-metallic pad to a carbon-ceramic disc unless the car maker lists it. Carbon-ceramic discs are usually large, so they also limit which wheels fit: see brake caliper clearance.
If you want to change pad type
- Start from the original type. The owner's handbook, the dealer or the part number of the original pad tells you what the car maker fitted. Matching it, as Bosch does, keeps the behaviour the brakes were developed with.
- In Europe and the UK, choose a pad with R90 approval for your car, listed on the box for your model and axle, and fit it in axle sets, as the regulation requires.
- In North America, compare the edge code with the original's: a different code means a different friction class, even if both boxes say "ceramic".
- Check the discs. The car maker sets a minimum thickness for each disc, and R90 requires a replacement disc's minimum thickness to be no less than the original's; a worn or scored disc should be dealt with before new pads go on.
- Bed in the pads to the pad maker's procedure; our guide to bedding in brake pads explains why.
- Work safely. If you change pads yourself, the car must be raised and resting on axle stands, never on the jack alone; wheel nuts go back to the car maker's torque. If the pedal feels long or soft, the car pulls under braking, or a warning light stays on after the job, have the brakes checked before driving on.
Wheels from Onyx Forged
Brake dust is worn material from the pad and the disc. Whatever the pad, the Japanese light alloy wheel makers' association advises cleaning often, because embedded dust is hard to remove (sources in our coating guide); our guide on cleaning alloy wheels and brake dust safely covers the method. Our guides on wheel finishes and their care and on ceramic coatings cover cleaning by finish. Onyx Forged does not recommend a size or an offset, and it does not recommend a brake pad either: the pad is the car maker's or an equivalent with R90 approval where that applies, and the choice between them is yours. The Onyx Forged design office works out a made-to-order wheel for the car as you describe it, brakes included, carbon-ceramic or not.
Frequently asked questions
Are ceramic brake pads better than semi-metallic?
Not in general. Sources agree ceramic pads are quieter and less dusty, and semi-metallic pads bite harder and suit heavy loads and repeated hard braking. The two that discuss pad life say ceramic lasts longer, without figures; they contradict each other on heat. Start from the type your car was built with.
Are ceramic pads the same as carbon-ceramic brakes?
No. A ceramic pad is a friction material used on an ordinary cast-iron disc. A carbon-ceramic brake is a composite disc, 50 per cent lighter than cast iron according to Porsche and Brembo, sold with its own pads.
Can I put ceramic pads on a car that came with semi-metallic or low-met pads?
In Europe and the UK, yes if the pad holds a UN R90 approval for your car and axle: the approval compares it with the original pad. Expect a different feel; the approval allows decelerations up to 15 per cent away from the original at the same pressure. Fit them in axle sets and bed them in.
Do ceramic pads stop the car as well?
A pad with R90 approval has been compared with the original on a test vehicle. The sources say ceramic pads have less initial bite, especially cold and wet, and may lose some power in long, repeated hard braking.
Why are semi-metallic pads noisier?
All the sources we read say they are, and none explains it with data. Pad makers also fight noise outside the friction material, with shims bonded to the backing plate, such as Bosch's rubber-core shim.
Which brake pads make the least dust?
The sources agree on ceramic or NAO pads, with dust that is finer and lighter in colour. Akebono says its ceramic pads "virtually eliminate" dust; that is a maker's claim, not a test we could check.
Are ceramic pads harder on discs?
The sources say the opposite: ceramic pads are less abrasive and discs last longer. None gives an independent figure.
What is the difference between ceramic and organic pads?
Organic (NAO) pads are a softer mix of rubber, carbon, glass and resin for light use; ceramic pads are denser and, according to ADVICS, consistent over a wider range of temperatures.
Where to go next
For the discs themselves, see drilled vs slotted rotors. Before buying wheels for a car with large or carbon-ceramic brakes, read brake caliper clearance. Onyx Forged is a French brand of made-to-order forged wheels, designed to JWL/VIA standards: see the catalogue.
Sources
- UN Regulation No. 90, replacement brake lining assemblies: consolidated documentation copy to 2017 (paragraphs 1.2, 5 and 6.1, Annexes 2 and 3) and Revision 3, Amendment 10 (in force 5 June 2023).
- Commission Regulation (EU) 2015/166, Article 7; GOV.UK, MOT inspection manual, section 1: brakes.
- FMVSS No. 135, 49 CFR 571.135; Transport Canada, TSD No. 135, Revision 5; Transport for NSW, brake assessment manual (2017).
- Washington State Department of Ecology, Better Brakes Law; US EPA, Copper-Free Brake Initiative (archived page).
- SAE J866, friction coefficient identification (scope).
- European Parliament, Euro 7 summary (13 March 2024); Department for Transport, explanatory memorandum (2 September 2026).
- Pad makers: Akebono, low copper and 2020 advertisement; Akebono EURO; ADVICS, in Vehicle Service Pros (6 July 2022); Bosch QuietCast, in FenderBender (1 January 2020); Brembo, Xtra pad.
- Carbon-ceramic and coated discs: Porsche, original brakes; Porsche Newsroom (2 July 2015); Brembo, carbon ceramic.
- AAA, ceramic vs semi-metallic brake pads (undated).
All pages were read on 16 October 2026.
The Onyx Forged design office.