winter tyres have two sets of tread wear indicators, one for snow and a second presumably for legality. It would be interesting to know what would happen if the tyre's tread were to be below the snow (4mm) depth and the driver had an accident in snowy conditions... not fit for purpose. As for fleet management companies, it's about time some driver tested their resolve - or are the vehicles meant to be parked up if the conditions are inclement?
The 4mm indicator is because that's the legal limit in parts of Germany in winter.
There's no requirement to fit winter or snow tyres (they're different) in the UK, just the 1.6mm global limit.
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And it is well documented that the wet grip drops dramatically , by 80% iirc, when the tread depth is below 4mm. I tend to agree from experience on my usual commute. Wet roundabouts became tricky when the tread got to 3/4 mm.
The 2mm limit is plain unsafe.
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And it is well documented that the wet grip drops dramatically , by 80% iirc, when the tread depth is below 4mm. I tend to agree from experience on my usual commute. Wet roundabouts became tricky when the tread got to 3/4 mm.
The 2mm limit is plain unsafe.
Being pedantic, it's 1.6mm, so even worse.
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the sooner the legal limit is raised to 3mm the better
Its not just tread depth, the age of the tyre is also important.
Went to a club meeting last Sunday and met up with a chap I had not seen since the early 90's. Still has the same car and its still on the Goodyear NCT's it was delivered on in the late 80's. they are 30 years old and even if they are not cracked (did not look at them closely) the rubber will be like concrete with zero wet grip.
IMHO a max of 10 years should be allowed and should be an MOT failure if they are older. Having said that I have had tyres younger than that with cracks severe enogh for Michelin to refund me 60% of the tyres value. When I showed them to the local MOT tester for his opinion he said he would be hapy to pass them. Fortunately Michelin did not agree.
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So if 10 years is a sensible age limit, then would a car with an older tyre in the boot as a spare be failed on the basis it's there with the intention to use it, or no point having it in the boot at all? (MOT test wise)
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The Spare wheel and tyre are not checked during an MOT, no legal requirement to have one fitted.
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the sooner the legal limit is raised to 3mm the better
Its not just tread depth, the age of the tyre is also important.
Went to a club meeting last Sunday and met up with a chap I had not seen since the early 90's. Still has the same car and its still on the Goodyear NCT's it was delivered on in the late 80's. they are 30 years old and even if they are not cracked (did not look at them closely) the rubber will be like concrete with zero wet grip.
IMHO a max of 10 years should be allowed and should be an MOT failure if they are older. Having said that I have had tyres younger than that with cracks severe enogh for Michelin to refund me 60% of the tyres value. When I showed them to the local MOT tester for his opinion he said he would be hapy to pass them. Fortunately Michelin did not agree.
The rate of deterioration from UV and oxidation depends whether the tyre is in the dark or not - an unused spare kept in the boot will last much longer than a road tyre.
Given that tyres can fail on examination well under 5 years old, then age is a poor way to limit life - the MoT examination is the best we have at the moment
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the sooner the legal limit is raised to 3mm the better
Its not just tread depth, the age of the tyre is also important.
Went to a club meeting last Sunday and met up with a chap I had not seen since the early 90's. Still has the same car and its still on the Goodyear NCT's it was delivered on in the late 80's. they are 30 years old and even if they are not cracked (did not look at them closely) the rubber will be like concrete with zero wet grip.
IMHO a max of 10 years should be allowed and should be an MOT failure if they are older. Having said that I have had tyres younger than that with cracks severe enogh for Michelin to refund me 60% of the tyres value. When I showed them to the local MOT tester for his opinion he said he would be hapy to pass them. Fortunately Michelin did not agree.
If I recall correctly, HJ himself (I think about 3-5 years ago) said that 6-7 years was the maximum he would recommend for the useful life of a car tyre, although this would vary due to the amount of direct sunlight that helps make the tyres hard and brittle.
I can vouch for that, as I replaced my Mazda 3's OEM Bridgestone ER30 tyres (awful after a year or so) after the car was 6.5 years old (and 40k miles approx), whereby the ride quality was very harsh and noisy, even though they had 4-5mm of tread left, and I had a couple of vary hairy moments on wet roundbouts. The difference between them and the Dunlop replacements was enormous (they were a more highly regarded tyre anyway), but the handling in the wet (my main concern) was back to what it was when the car was new.
Fortunately as these replacements were better generally, this good performance has barely changed in the 5 years since then (though significantly less mileage under its belt [about 22k]). It'll be interesting to see if problems with noise and wet handling start to occur again in the next few years - perhaps the tyre technology has improved the useful life to nearer 10 years that some BRs have thought as the max. Personally speaking, I always go on how the tyre performs rather than tread depth alone.
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Being pedantic, it's 1.6mm, so even worse.
I was referring to the policy in the original post.
Today's Guardian has an article about tread depths and premium v budget tyres .
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Today's Guardian has an article about tread depths and premium v budget tyres .
I would be interested to read that. In my poinion some tyres even on their last legs have better wet grip than other brand new tyres.
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Today's Guardian has an article about tread depths and premium v budget tyres .
I would be interested to read that. In my poinion some tyres even on their last legs have better wet grip than other brand new tyres.
I doubt that very much Stanb, given that the main factor in wet weather grip is the ability to disperse the water. Which in turn means that the main factor in that, is tread depth. Maybe a part worn 'quality' tyre will be more effective than a new one, due to better design, but not one on its last legs, which will be much more likely to aquaplane.
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"I doubt that very much Stanb, given that the main factor in wet weather grip is the ability to disperse the water. Which in turn means that the main factor in that, is tread depth. Maybe a part worn 'quality' tyre will be more effective than a new one, due to better design, but not one on its last legs, which will be much more likely to aquaplane."
Try any car on cheap Chinese tyres and you'll see it's true. I bought an Astra recently on cheap rubber. It's fine in the dry but slides everywhere in the wet despite all being nearly new tyres. A quality brand at minimum tread can be better than a cheap brand at double the depth.
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A set of tyres should last 20-40k depending on driviing style, type of car, wheel alignment.
A good quality replacement set of tyres is typically in the range £2-400. Cheaper for small ditch finders, more for premium high performance. Last set on my Octavia (Michelins) were about £220.
Taking a simple average - 30k and £300 works out at about a penny a mile.
I willingly replace tyres when they are down to about 3mm. It probably costs an average of about £20pa compared to running them to the minimum. Irrespective of driving style it is better to be confident that one of the three (steering, brakes) most important components on the car is up to scratch.
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"I doubt that very much Stanb, given that the main factor in wet weather grip is the ability to disperse the water. Which in turn means that the main factor in that, is tread depth. Maybe a part worn 'quality' tyre will be more effective than a new one, due to better design, but not one on its last legs, which will be much more likely to aquaplane." Try any car on cheap Chinese tyres and you'll see it's true. I bought an Astra recently on cheap rubber. It's fine in the dry but slides everywhere in the wet despite all being nearly new tyres. A quality brand at minimum tread can be better than a cheap brand at double the depth.
Ok, i may concede that on a road which is just wet, that may be the case, but standing water?.
But also, you are talking about a quality tyre at minimum tread, i.e, 1.6mm, versus a cheap brand at double the depth, so 3.2mm. Stanb was talking about a new 'cheap' tyre (which will have around 8mm tread) versus a quality tyre on its last legs. I still think that with that comparison, on standing water, the cheap tyre will give more grip?.
But i could be wrong, wouldnt be the 1st time!
Just to point out though, i wouldnt use cheapo tyres anyway. When my van tyres need replaced, i buy a quality set off ebay (most recently michelin all weather) and get the garage i use to fit them.
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Today's Guardian has an article about tread depths and premium v budget tyres .
I would be interested to read that. In my poinion some tyres even on their last legs have better wet grip than other brand new tyres.
I doubt that very much Stanb, given that the main factor in wet weather grip is the ability to disperse the water. Which in turn means that the main factor in that, is tread depth. Maybe a part worn 'quality' tyre will be more effective than a new one, due to better design, but not one on its last legs, which will be much more likely to aquaplane.
Perhaps, though the tyre compund will also have a large impact, given that harder tyres are a lot worse in the wet than softer ones, so if an expensive one has a softer, but higher quality makeup (including tread pattern), it will perform better even when the tread depth is lower than a lower quality tyre. Michellin's cross climate is a good example of this (HJ wouldn't recommend it if it wasn't) where its well worth paying a premium to get a longer 'sweet spot' in the life of the tyre than the cheaper end of the market.
I'd personally never go for the really budget makes (otherwise known as ditch-finders) given they are either a much harder compound (great on life, very poor on handling, especially in the wet etc) or very soft (very short lifespan, not economic), even if (as I am at the moment) I was doing low annual mileages. My reasoning is that why spend several £000s on a good car, then scrimp on the only point of contact with the road surface?
Buying expensive tryes isn't necessarily guaranteeing a good ride and handling, hence why the tyre reviews by both tests AND owners' real-world experiences are worth reading (especially when they pertain to our own cars) before choosing. Again, I always go by the way the tyres work/feel/look before changing - no sense in changing them just because they are X years old, but will do so if the handling and/or ride quality has diminished sufficiently to become an issue, as well as their visual condition.
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My Passat diesel and my Octavia diesel both only got around 14000 miles per set of tyres. Yes, the front and rear wore almost at the same rate and wore evenly across the tread with no signs of misalignment.I changed them when the fronts got to 3mm or so.
Latterly I used several sets of Barum Bravuris (made by Continental) after I found that the OE Michelin replacements did not wear well.
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My Passat diesel and my Octavia diesel both only got around 14000 miles per set of tyres. Yes, the front and rear wore almost at the same rate and wore evenly across the tread with no signs of misalignment.I changed them when the fronts got to 3mm or so.
Latterly I used several sets of Barum Bravuris (made by Continental) after I found that the OE Michelin replacements did not wear well.
That seems a very high wear rate.
My BMW 325d (RWD) fitted with big Msport wheels goes through rear tyres roughly every 18k miles (that's changng at 3mm, and running premium tyres). The first set of fronts lasted 35k miles.
Only getting 14k from the rears on a FWD car seems extraordinary.
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Does tyre compound make a difference in the wet?
Tread depth, tread pattern and sipes make the difference - remember Michelin X tyres, best in the wet and hard compound so lasted for "ever".
Tyre compound makes a huge difference in the dry, or cold in the case of winter tyres.
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Does tyre compound make a difference in the wet?
Tread depth, tread pattern and sipes make the difference - remember Michelin X tyres, best in the wet and hard compound so lasted for "ever".
Tyre compound makes a huge difference in the dry, or cold in the case of winter tyres.
I remember Mich X tyres well, but because they were most appalling tyre in the wet i've ever had the misfortune to drive on, and the ZX that followed it no better.
My '69 Vauxhall Ventora was on MichelinZX's and in the wet it could only be described as terrifying, that was the first time i ever scrapped a set of tyres still with deep tread, many times since various makes, and Mich's have featured as late as 8 years ago in being removed before time.
Replaced with a set of the then new Goodyear Unisteel, whch transformed the car and enabled the use of its quite reasonable power.
I've had some really frightening experiences years ago on Michelin lorry tyres, especially when getting to recut compound, ironically i had a new tractor unit issued to me once, and i got most aggrieved because my then boss had the new Mich drive axle tyres removed (to use for steer axles) and a set of Kenprest remoulds fitted, talk about egg on face though, those Kenprests to this day are the best wet grip lorry tyres i have ever driven on.
Compound is important for wet grip, as a rule the softer and faster wearing are going to grip better, one of the best current tyres for wet grip are Uniroyal Rain Expert and Rainsport (lower profiles), they don't wear particularly well but they stick like the proverbial and i usually get some sent in time for daughter's tyre replacements.
As for the country of origin, i have always avoided far eastern tyres (and to be honest not that impressed with Japanese either) but the new set of Nankangs that were fitted on my Landcruiser when i bought it continue to surprise with just how good they are on the road in the wet, snow grip i don't yet know about.
Edited by gordonbennet on 16/07/2017 at 14:08
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There are two factors at play here. The tread depth will effect the tyres resistance to aquaplaning but its near impassible to aquaplane below 50mph, wide tyres are worse than skinny tyres. On plain wet roads that have minimal depth of standing watter its the tread compound that decomes the dominant factor. The micro structure of the rubber grips the road surface. The newer silica compounds allow softer rubber that drapes over the surface texture of the asphalt to grip better in the wet. These newer compounds also have good wear resistance because they conduct heat better than the traditional carbon dust blended into the rubber. Another factor is the ratio of rubber to void, some wide tyres have only 50% of the tread area as rubber and 50% void to increase its capacity to disperse watter at low tread depths.
The early Chinese tyres that SLO mentioned were strange things, they had a high persentage of natural rubber, very expencive stuff and very tough but its wet grip is very poor. Last forever though.
Edited by Stanb Sevento on 16/07/2017 at 14:49
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I had cheap Chinese ditchfinders on my C5, when winter arrived I spent a couple of hours towing dozens of colleagues' stuck cars out of the company car park, including a 4WD Audi S4 shod with worn premium rubber.
I fitted the same ditchfinders (Nankang N607s) to the missis's C3, which I was driving on the motorway in torrential rain, I had (coincidentally) another Audi up my chuff even though I was overtaking, not lane hogging. Well, I spotted a huge puddle ahead and lifted off gently, the little light C3 didn't budge an inch despite hitting the puddle at 70+ mph, Mr Audi spun into the central reservation - missing me by inches.
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I had cheap Chinese ditchfinders on my C5, when winter arrived I spent a couple of hours towing dozens of colleagues' stuck cars out of the company car park, including a 4WD Audi S4 shod with worn premium rubber.
I fitted the same ditchfinders (Nankang N607s) to the missis's C3, which I was driving on the motorway in torrential rain, I had (coincidentally) another Audi up my chuff even though I was overtaking, not lane hogging. Well, I spotted a huge puddle ahead and lifted off gently, the little light C3 didn't budge an inch despite hitting the puddle at 70+ mph, Mr Audi spun into the central reservation - missing me by inches.
What often happens is that certain tyres, even if the 'same' brand and model, can react significantly differently if they are of different sizes, age/condition and on different cars. Mr. Audi may well have had tyres that were very low profile and worn, neither of which are great for handling in poor weather as we see on F1. Its also how the cars are driven as well - I suspect the hard braking (as opposed to you backing off only) by the Audi contributed to their spin, given that's what happens in icy conditions. Sudden braking/manouvres in poor road conditions are dangerous.
I've seen many tyres on premium make cars over 3yo that have almost no tread left - either because the [latest] owner spent all their money on buying and not running the car (maintenance, a common theme on older premium cars) or because they are boy racers and forgot to notice the state of the tyres until its too late. I know quite a few people who've failed MOTs due to tyres worn down to the 'carcass'.
I would suspect that the cheapo tyres will hold the road less well than using an equivalent premium tyre of the same size and (resonable) life on the same car in the same conditions/road. Occasionally a cheaper brand tyre does better than expected or premium worse in tests, but in the main you get what you pay for, all other things being equal., the same goes for new tyres vs. old (I mean 15-20 years old) ones, even if they've been stored out of the sun and in moderate temperatures - the technology moves on enough within a 10 year period to make a meaningful difference.
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