interesting article here

Car tyres produce vastly more particle pollution than exhausts, tests show

Toxic particles from tyre wear almost 2,000 times worse than from exhausts as weight of cars increases

www.theguardian.com

the TL;DR is car tyres can emit 20 time more ultra fine particles than a car exhaust.

Drive it hard / the amount increased by a factor of 5.

BEV’s are heavier - but are often driven more gently.

new tyres were 2-4 times worse than used tyres (they didn’t define what a used tyre was)

final point (important one) that the chemicals in the tyres and thus particles are pretty much unregulated. The toxicity of a ‘bad’ tyre can make it much much worse

Yes, I thought it was an interesting and well balanced article.

The lack of regulation of the chemicals making up tyres was an interesting point, as well as the suggestion that changes to / regulation of the chemicals to minimise the problem should be straightforward.

 

I wonder if the low rolling resistance tyres wear at a different rate than normal tyres?

 

According to this article tyre and brake particulates are roughly proportional to vehicle weight, with driving style also having a significant effect as particulate generation is also roughly proportional to deceleration rate.

The figures suggest that tyre and brake particles are produced at roughly the same order of magnitude as each other.

EVs are perhaps 20-30% heavier than similar ICEs (e.g. comparing the Niro variants), so will result in greater tyre and brake particulates being produced - potentially as much or more than the reduction in tailpipe emissions vs an ICE.

However, EVs using predominantly regen braking might reduce brake particulates by 80+% (my guess - even on the weak regen on my PHEV means much less friction brake usage) - likely more than offsetting the increase in tyre wear particulates due to increased weight.

Drivers being more aware of efficiency (eg due to range/charger anxiety, or electricity costs, or just a desire to maximise the efficiency) may also reduce average deceleration rates, which could also significantly reduce brake and tyre particulate generation.

 

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However, EVs using predominantly regen braking might reduce brake particulates by 80+% (my guess - even on the weak regen on my PHEV means much less friction brake usage) - likely more than offsetting the increase in tyre wear particulates due to increased weight.

This, I'm about to go into my 5th year of ownership of a Golf GTE PHEV and my brake pads are still only down 10% !

 

A good article however i would suspect that HGV will contribute far more than cars.

 

Sorry but they didn’t even test an EV….. they added 500kg to an ICE…..
EV’s generally use low rolling resistance tyres, the test didn’t, it used the same tyres on the ice car
The weight distribution of a battery gives a better 50-50 split, adding 500kg to a front heavy car doesn’t, all it does is make things worse…

Why not take ie a Nero and do a real test on genuinely similar cars powered by different fuels and then you have science. This piece is just another load of BS guesswork

 

Sorry but they didn’t even test an EV….. they added 500kg to an ICE…..
EV’s generally use low rolling resistance tyres, the test didn’t, it used the same tyres on the ice car
The weight distribution of a battery gives a better 50-50 split, adding 500kg to a front heavy car doesn’t, all it does is make things worse…

Why not take ie a Nero and do a real test on genuinely similar cars powered by different fuels and then you have science. This piece is just another load of BS guesswork

And considering this was reported in The Guardian, i'm sure they had easy access to a number of EV types they could have asked to use.

But the most important fact is this. Yes any kind of pollution that we all ingest is very bad, but tire particles do not increase global CO2 levels, and we have about 30 years to sort that out before it is all moot.

That is kind of 100% the point of EV's vs ICE, and it should be upto the tyre manufacturers to make better cleaner tyres, so reports like this are good. But let's not loose site of the existential threat that man made global warming (due to rising CO2 levels) currently poses.

 

I'd also think road quality could make a difference. Does the rough ass tarmac scrub tyres faster than the high quality smooth stuff?

 

I guess people have never looked at their tyres and wondered where all the tread that used to be there has gone, so I suppose the research that Emissions Analytics have been pushing for the last few years around this at least might make people think about it.

However, what we can actually do about it as consumers is debatable, and it will also be seized upon by certain agenda pushers as a good news story for ICE vehicles and another stick to hit BEVs with.

It’s correct to highlight the issue, and if there are toxic compounds that can be changed to make tyre particulates less impactful then manufacturers should do so.

What’s not talked about are road surfaces. The poorer the quality of the road surface, the faster tyres wear, again not something the general public have control over. Proper road maintenance would help this and many other areas.

Subjectively speaking, my own feeling is that tyres on my BEV vehicles wear at a similar rate to my old ICE ones, brakes last noticeably longer on BEVs.

If vehicles could get lighter then it would certainly help in all sorts of areas though.

 

There is nothing in any of these stories to suggest EVs are in worse than ICE. Obviously toxic precursor chemicals in water runoff is an issue that needs tackling. That's a tyre manufacturing/regulatory problem. Note also how the article is bouncing around between airborne particulates ( ie cause if respiratory illness) and runoff to watercourses which is a specific fish toxicity problem and if course a problem for the greater biosphere us included. What can be done? Drive a bit slower, drive gently ( acceleration, cornering and braking). Keep your steering aligned. All things that driving an EV naturally encourage - Tesla's excepted.

 

The article was not about BEV tyres - about tyres in general. I’d urge people to read the article rather than the headline - as the main takeaway was that the toxicity of the tyre material/rubber was really important and at present unregulated and largely unknown.

The article also made the point that wear was proportional to weight and BEV’s are presently heavier. To counter this it argued that the weight difference between BEV and ICE will decrease to nothing by 2025 and that BEV driving style was often more careful.

Tooks raises the important point that most of us don’t think about where that mass of tyre rubber goes… 30million cars in the Uk - let’s say 5-10 million tyres a year… that’s a lot of rubber (and other stuff) that has to go somewhere!

another important detail from the article was that very little rubber was worn off as large (>23 micron) particles - most were in the worryingly small size (the size that easily find their way into peoples lungs…)

 

The article was not about BEV tyres - about tyres in general. I’d urge people to read the article rather than the headline - as the main takeaway was that the toxicity of the tyre material/rubber was really important and at present unregulated and largely unknown.

The article also made the point that wear was proportional to weight and BEV’s are presently heavier. To counter this it argued that the weight difference between BEV and ICE will decrease to nothing by 2025 and that BEV driving style was often more careful.

Tooks raises the important point that most of us don’t think about where that mass of tyre rubber goes… 30million cars in the Uk - let’s say 5-10 million tyres a year… that’s a lot of rubber (and other stuff) that has to go somewhere!

another important detail from the article was that very little rubber was worn off as large (>23 micron) particles - most were in the worryingly small size (the size that easily find their way into peoples lungs…)

As EV drivers I think we all know the issues surrounding pollution be that from the power to make electricity or the rubber on the road. The trouble with this report is it is ICE car specific and then they guess that a heavier EV is worse. That’s not science, it’s dressed up BS….How can adding 500kg to the passenger compartment of a front heavy ICE tell you effect that the additional weight has on a vehicle with 50-50 weight distributions?

 

No doubt action will be needed on the tyre pollution issue, if only by changing the rubber formulations to remove the hazardous chemicals.

At some point though the focus will need to move on from vehicles to the other sources of air pollution because it is starting to reach the point of diminishing returns. It's a bit crazy that vehicles are now so clean that we are starting to worry about the rubber from the tyres, meanwhile people are still installing solid fuel burning stoves and fires with no automatic combustion controls, no catalysts and no filters.

 

It's bonkers that we seem to have only just realised that the wearing out of tyres effectively just dumps millions of tonnes of rubber into the environment when there are such stringent regs on tyre disposal.
Same can be said for lots of other things. For example I painted my shed yesterday using 9 litres of fence paint. No doubt that contains millions of nasty chemicals that will be slow released into the environment over the next 5 years.
Maybe it's time to go back to natural rubber tyres?

 

Same can be said for lots of other things. For example I painted my shed yesterday using 9 litres of fence paint. No doubt that contains millions of nasty chemicals that will be slow released into the environment over the next 5 years.

Emissions from paints has received a lot of attention with regulations to reduce the volatile organic compounds which contribute to air pollution, which is why a lot of paints are now water based and the oil based paints have been reformulated to reduce the volatile content to the bare minimum.

If your fence paint is one of the typical products then most of the 9 litres will have been water.

 

So, time to tax tyres not fuel?

 

It would make more sense for car tax to include an element reflecting the cars weight.

 

Interesting it was a Mercedes’ c class they used for testing as Mercedes’ were talking about this issue a few years back when the anti diesel talk started. For me there are 2 types of pollution the one killing the planet ie CO2 and that killing animals (inc us) with particulate emissions. I drive electric because of the first as I worry that the move from diesel back to petrol is going to cause more issues than it saves and indeed this article indicates that with ref to the fact tailpipe emissions are fall8ng drastically.
Re the particulates clearly BEV are better in relation to brakes becuase they do wear their brakes far less, so the question is how much worse are they down to weight 10% 20% we are not told only that weight is understandably an issue leaning to higher levels of wear of tyres.
I am concerned about the chemical issues as it occurs to me the cheaper tyres will probably have less latest technology in them ie cheaper chemicals blended in cheaper ways and with poorer technology for wear. I think the use of cheap Chinese tyres now so prevalent everywhere is a real cause for concern and should be a starting point for any controls with pressure on the big names to explain how they manufacture their tyres and what they are thinking re wear rates etc. Considering the role tyres play the safety of a vehicle it never ceases to amaze me people buy anything other than the tyre used by the vehicle manufacturer but thatis just me but it does seem some of the cheap tyres wear more quickly from a friends experience.
Finally road surface it would be interesting to know if the smooth tarmac so prevalent here where I live is better than the surface dressed road or the concrete carriageways loved by the U.K. and the US. If that is the case then govs have to readdress how they maintain their road systems and you can be sure that some countries that idea will not fly at all as maintaining infrastructure is something they are just not interested in naming no names.

 

Re the particulates clearly BEV are better in relation to brakes becuase they do wear their brakes far less, so the question is how much worse are they down to weight 10% 20% we are not told only that weight is understandably an issue leaning to higher levels of wear of tyres.

How do we know the weight is worse in a BEV where it is evenly split between front and back. You cant just add 500kg to the passenger compartment of an ICE with a heavy engine at the front and then guess the result. Sure added weight is worse in a C Class Merc.... so that information tells us front engine, rear drive heavier cars are worse. Does it tell us a heavy long car like a S class is worse than say a lighter shorter but much higher centre of gravity SUV or what effect it has if the weight is even split front to back? The answer is no it doesn't......

 

interesting article here

Car tyres produce vastly more particle pollution than exhausts, tests show

Toxic particles from tyre wear almost 2,000 times worse than from exhausts as weight of cars increases

www.theguardian.com

the TL;DR is car tyres can emit 20 time more ultra fine particles than a car exhaust.

Drive it hard / the amount increased by a factor of 5.

BEV’s are heavier - but are often driven more gently.

new tyres were 2-4 times worse than used tyres (they didn’t define what a used tyre was)

final point (important one) that the chemicals in the tyres and thus particles are pretty much unregulated. The toxicity of a ‘bad’ tyre can make it much much worse

S'funny how I have been 'shouted down' here for mentioning this in the past, now it gets likes for you mentioning it.

I don't understand people, guess I never will.

 

The article is full of nonsense and confusion.
Tyre wear particulate emissions are by weight mostly non respirable an of little or no danger to humans. Run off of larger particles into rivers may be an issue for aquatic life. More research needed here. Respiration of particulate matter is an area I have some experience in. Particles below 0.5 micron (500nm) are most likely to reach the alveoli where exchange of gasses into the blood takes place. 23nm (.023 micron) particles will mostly be breathed out without transfer to the blood, but some tiny percentage of the mass of the particulate matter in the respirable range may possibly reach the bloodstream.
I will try to get hold of the original research and see quite what the real position is. The Graun, however, have really made a muddle of the data and deliberately made obtuse and irrelevant statements about tons of matter produced by driving 1km.

 

The article is full of nonsense and confusion.
Tyre wear particulate emissions are by weight mostly non respirable an of little or no danger to humans. Run off of larger particles into rivers may be an issue for aquatic life. More research needed here. Respiration of particulate matter is an area I have some experience in. Particles below 0.5 micron (500nm) are most likely to reach the alveoli where exchange of gasses into the blood takes place. 23nm (.023 micron) particles will mostly be breathed out without transfer to the blood, but some tiny percentage of the mass of the particulate matter in the respirable range may possibly reach the bloodstream.
I will try to get hold of the original research and see quite what the real position is. The Graun, however, have really made a muddle of the data and deliberately made obtuse and irrelevant statements about tons of matter produced by driving 1km.

I am always happy to listen to cogent scientific evidence based experts and unlike a certain politician I am not fed up with experts far from it we need more experts helping us understand our world and how to navigate it.
The article seemed fairly ok of its type and chimed with other material I had read which stuck with me ie Mercedes’ own publicity about the particulate emission issue to which I also had a dose of scepticism and well you would say that….but they were just trying to point out particulates were not just produced by engine emissions but also tyres and brakes.
What is highlighted here I think is how so many of us make many of our decisions not on scientific papers but on media reports inc social media and advertising media. Critical thinking then becomes very important to help one sort the wheat from the chaff a reason why forums like this appeal, even though they can be a bit of an echo chamber at times, as they throw up challenges and debates and make one think or at least they do me😉

 

My Ioniq tyres have shed a load of particles of various sizes over the last 21,000 miles and both of the fronts are now down to 4mm tread. The rears are still fairly meaty. Can I divert slightly to ask a question?

Ioniq is front wheel drive of course. There are mixed opinions on rotating the wheels/tyres. The main idea is to even out wear, and to diagonally swap the rears to the front, and to swap the fronts to the rear but keep them to the same sides.

But others ( some are pros ) have told me to not swap at this stage but to wait until the fronts are down to 3mm, or 2mm at worst, and then fit the halfway decent rears to the front and buy two new ones for the rear.

In the past, I have always rotated to protect the fronts a bit and wear the rears down to a similar limit and then buy four new tyres. As per the main opinion. But is there some merit in opting for the second opinion? Apart from not shelling out for four tyres at once. As I intend to change cars in the next year or so that appeals to me.

Whilst on this subject, will the car automatically adjust the TPMS units to show which wheel is on which corner after swaps/ renewals take place or will it need reconfiguring at a tyre fitters?

Sorry for the diversion from emissions but its not worth starting a new thread.

 

I think, no net benefit. The advantage in rotating F-R is that the tyres wear together and they remain better matched for the stability control and the laws of physics to do their job. The advantage to not rotating is what you just said, you don't fork out for 4 at once, which might be a big deal if you are leasing a car and might get away with replacing only 2 (or 6) tyres rather than 4 (or 8). It is a bit of a gamble sometimes, if you have a 2 year lease and you rotate after 1 year then you might not have to buy any tyres at all, or you risk buying 4. Do the arithmetic.

Buy remoulds if you can find them, and if you have a concern about the environment.

 

I wonder if making roads of rubber and tyres of stone would make any difference? 😁

 

If tyre particles were so hazardous then F1 would be banned, when you see the marbles from their tyres. Driving gently will give the best longevity. I'd frankly be more concerned at the amount of plastic we are putting in the environment, and some folks total inability to dispose of their rubbish properly, don't just toss it aside.

 

F1 has carbon footprint issues anyway without worrying about tyres…

your last line is apposite though - because we are just tossing away all the material that wears off tyres…

 

FUD, watch this.

Cheers

 

The guardian article has been hijacked on various Twitter threads - by ardent EV’ers saying ‘ITS NOT TESTING AN EV’ and by ICE’ers saying ‘I TOLD YOU EV’s ARE WORSE’ etc….
All of which Rather disappointingly ignores the issues that particulate pollution from tyres may be a major health issue regardless of where it comes from and that the toxicity of the particles is (a) highly variable (b) largely unknown and (c) not really regulated.

it’s these points that matter!!! 🤦‍♂️

 

It is disappointing but not surprising. Social media does not really do nuance, and the fact that net zero has become the latest battle zone for a particularly execrable bunch of politicians has not helped.

For me it is really simple - my son's old infant school is near a busy main road, as no doubt are many other schools, and if air quality is poor in the local area then it should be addressed.

Honestly I don't give a **** about whether EVs might be more or less of a problem than ICE cars, or HGVs are worse than either - tyres generate particulates, so measure it, assess it, report it and if necessary regulate it. Then there will be one less excuse for those with an agenda to argue against EVs.

 

This (and many others like it) could help with both the number of tyres sent to landfill and the amount of particulates emitted (no over or under inflation):

Innovation : the VISION concept | Michelin

Visionary, innovative… Michelin is thinking outside the box with its VISION concept, which illustrates the Group’s sustainable development model for 2050. An ambition that confirms Michelin’s innovative strength, and in particular its singular expertise in the field of high-tech materials and...

www.michelin.com

I guess now that it's being viewed as an issue it'll be one of the factors that they design for.

 

Interesting wonder what effect they have on tyre noise and thump and bump as they go over defects in the carriage way. Be quite intrigued to try a car with them.

 

The police aren't going to like this - their Stingers will be useless on these!
I note they're testing on Chevy Bolt (alomng wiht other ICE no doubt) - wonder what the Efficiency/Rolling Resistance are?

 

So harder compound= lower particle emissions but = less grip = more accidents.

The you have to ask if the reduction in life expectancy is worse from the higher accident rate than the increase in life expectancy from the reduced particle emissions.

Don't know the answer - just adding another factor that seems to have been overlooked!

Are we dancing on the head of a pin again?

 

I think you may be assuming that this is a simple system with only one variable, where tyre grip is inversely proportional to hazardous particle generation.

Just off the top of my head there are 3 possible approaches:

1. Reduce the number of particles generated. This is where tyre hardness might be a factor, along with road surface etc.

2. Reduce the toxicity of the particles generated. This is I think the main focus of the OP - reporting and regulation of the elements of the tyre compound would improve this.

3. Change the size of the particles generated. I am not a materials scientist, but it doesn't seem unreasonable that the tyre compound could be changed so that the bulk of the tyre particle size distribution falls outside the main hazardous range (<23 nm?).

It is not really any different to engine emissions regs or asbestos in brakes and clutches. Manufacturers are not going to do anything unless they are forced to. So measure the problem and regulate it as required. Sure the tyre manufacturers will lobby against it,. then they will sort it, because if they don't their competitors will.

 

Add noise to the mix. As regulations on emissions gets tougher, so do regs on noise. Many cars are already pretty quiet at the exhaust so may be increased pressure on tyres to be quieter too

 

Some good posts here. Something for the material scientists to get stuck into! It’s an interesting issue as we’re now almost as interested in the material that is removed (worn) as remains.

Also worth remembering how particle diameter relates to volume - so if you can design a tyre to wear in particles twice as large - then that’s - cubic reduction in particle number.

 

This is a really good analysis of the article - and a counter point why it may not be as bad as exhaust emissions (from a Prof of nano particles iirc). Posts 9-10 most interesting:

 

I don't think anyone IS declaring that tyre emissions are bigger health concerns than exhaust particulates.

The key is that they MAY be, and the question therefore is; are they or are they not and how do we measure and monitor this?

"This thing MAY not be as bad as we first thought, therefore we don't have to bother concerning ourselves about it" sounds to me a classic logical fallacy some folk try to dodge issues that they are not cognitively willing to engage with.

My engineering intuition says that 20 years ago a Euro 2 diesel would put out far more concerning particles in its exhaust than from its vulcanised natural rubber tyres.

However, can we say that the particle emissions from a Euro 7 exhaust are worse than a synthetic rubber plastic tyre of the future made from material combinations that no tyre to date has been made from? ... of course we cannot.