The Truth About Worn Tires?

[SubLGT]

http://www.eurekar.co.uk/articles/2017-05-15/michelin-reveals-all-about-worn-tyres

Quote:
To debunk the myth that tread depth alone is critical, the tyre maker [Michelin] has just staged a demonstration at its Ladoux test track in France to show exactly how worn tyres perform…...
According to Michelin, safety is all about general tyre performance, not just tread depth and the results from Ladoux were an eye opener.

Michelin says there is no direct link between accident levels and tread depth and has also flagged up a study by Ernst and Young which estimates that increasing minimum tread depth from the current 1.6mm [1/16 inch] to 3.0mm would cost motorists in Europe almost £5 billion.

Point taken then that better quality tyres out-perform cheaper alternatives at the limits and to back that up Michelin produced the results of tests it has carried out on 24 different sets of tyres showing the differences in stopping distances when new and worn.

"All tyres are not equal when they are new - and what our tests at Ladoux have shown us is that tyre performance is even less equal when worn," said Terry Gettys, Michelin's boss of research and development.

"In fact the differences are very much accentuated once a tyre is in the latter stages of its life. Quite surprisingly we have discovered that some tyres worn to the legal limit have a wet braking distance virtually the same as some new tyres."


According to the article, there were wet and dry braking tests, and wet and dry skidpad tests. But no mention of hydroplaning tests.

 

[otis24]

Thanks for posting!

 

[IndyIan]

Perhaps a rule that all-seasons or winter tires need to have a reasonable minimum depth in winter time would make more sense?
I've never found worn decent summer tires a problem at all, even for hydro planing, but I'm reasonably smart about it. No 80mph driving in a downpour, etc.
I'm sure at some speed and water depth, the tread depth is important, but probably at a not much higher speed, tread depth becomes irrelevant, and your aquaplaning with any tire.

 

[E150GT]

I bet tire width and vehicle speed have more to do with hydroplaning than anything. I always try to buy the best tires I can afford. You can feel the difference. When I got my Mazda 3 it had Bridgestone turanza EL400 and I could tell after about 20k miles they didn't have the same traction in the wet even though they still had excellent tread

 

[WobblyElvis]

Living in a big city that has a good snow removal crew, I almost never have to drive in snow but I do have to drive on a thin layer of ice quite often. Usually there is a little snow left over and with a few freeze thaw cycles the roads get covered in a thin mix of snow/ice. Consumers Reports tests tires for performance on ice and some all seasons tires are rated as good as snow tires in this situation. I bought some of these all season tires and have to agree they stick to ice really well so that's what buy. I do notice that their ability to work well on ice diminishes as the tread depth is reduced.

 

[mightymousetech]

So basically, buy [censored] tires you get [censored]. Imagine that.

I could have told you this. When we are racing, we stay on slicks until there are puddles on the track. Still faster without any tread at all. Most important thing is rubber compound, and how old/heat cycled it is.

Problem is, you can't tell how good a rubber compound is by looking at it, they are all just round and black.

 

[HangFire]

Originally Posted By: mightymousetech
So basically, buy [censored] tires you get [censored]. Imagine that.


So I'm scratching my head at this. Why would Michelin do this test? If there is a push to require a new minimum tread depth in the EU, Wouldn't all tire manufacturers profit from such a standard? While I'm sure the pollution figures are close enough, I think it gets down to the ratings push by Michelin at the bottom of the article. I'm sure Michelins would rate above the cheap Asian imports...

Researching I just found this, but it doesn't seem to have the 2016 changes it expected:
http://www.blackcircles.com/general/tyre-labelling/tyre-label

Seems wet tire ratings are already in there. I guess Michelin wants WORN WET tire ratings.

 

[andyd]

1/16 remaining tread definitely limits the safe speed that a car can travel in the wet. . AKMHIK. I bought a 528e project with well worn Coopers on it. They passed MA state inspection, barely. I could drift at 30 mph on a heavy dew, let alone rain. Dry they were fine and they wore like iron.

 

[Dyusik]

I have taken a chev lumina to 90>120 mph (speedo pinned, one of thos 85 mph speedos) through this bridge (right to left, the on ramp from one hwy to the other), in a down pour with maybe a 1/8 of an inch standing water and wires sticking out of 3 out of 4 tires.
Yes, possibly the top 10 dumbest things I have ever done, but point is a good tire will be a good tire until it no longer resembles one.

 

[mightymousetech]

Originally Posted By: andyd
1/16 remaining tread definitely limits the safe speed that a car can travel in the wet. . AKMHIK. I bought a 528e project with well worn Coopers on it. They passed MA state inspection, barely. I could drift at 30 mph on a heavy dew, let alone rain. Dry they were fine and they wore like iron.


That is the whole point of this article. Buy good tires and they are better in the wet at 1/16" than many cheaper tires at full tread depth.

I would rather be on zero tread depth slicks in damp weather than a cheap tire.

 

[Quattro Pete]

Originally Posted By: HangFire
Originally Posted By: mightymousetech
So basically, buy [censored] tires you get [censored]. Imagine that.


So I'm scratching my head at this. Why would Michelin do this test? If there is a push to require a new minimum tread depth in the EU, Wouldn't all tire manufacturers profit from such a standard?

Michelin would lose their competitive differentiation if minimum tread depth was increased.

Right now, Michelin can say that their tires offer better performance at 1.6mm tread vs competitors, so their marketing dept will spin it that you get more useful life out of their tires, and therefore their tires are more cost effective because you can run them until they are almost bald.

But if the minimum tread depth is increased to 3mm, then Michelin's advantage disappears because drivers will be required to replace their tires early. At 3mm, most tires still perform well enough. But at 1.6mm, only Michelin tires perform well, or so they claim.

 

[supton]

Hmm, would Michelin be pushing (inadvertently?) for wet testing on all tires? I mean, you could have some sort of A/B/C/D table for any given tire, where testing has confirmed that tires of A grade can be used down to 2/32's, B grade to 3/32's, C to 4/32's, etc. That way a consumer could have choice, much like how today one has choices in treadwear.

 

[CKN]

Really don't understand this thread. I had OEM Michelin MXV4 and they were terrible in rain right off the show room floor.

They would break loose from runoff from the city's overflow water from the green strip in the middle of the street.


I would believe ANYTHING on what they say their wet performance is-because I have owned some and they were terrible.

 

[HangFire]

Originally Posted By: CKN
Really don't understand this thread. I had OEM Michelin MXV4 and they were terrible in rain right off the show room floor.

They would break loose from runoff from the city's overflow water from the green strip in the middle of the street.


I would believe ANYTHING on what they say their wet performance is-because I have owned some and they were terrible.


I had some Primacy MXV4's as well, and wet performance was just OK to 30K and awful to 62K when I replaced them with 5 to 6/32" tread depth left. So I can relate to what you're saying. But get this, the tires before were cheapies (Telestar Weatherizer) that had worse wet traction at zero miles than the Michelin's had at 62K. The Telestars were a tire the dealer put on new when I bought the car with 33K on it. I replaced the Telestars at less than 15K because I didn't want to die.

So, as bad as my MXV4's were, there are worse new tires out there, which kind of makes Michelin's point. (The MXV4's were replaced by Continental PureContacts Eco+, which is a better wet tire at 33K than the MXV4's ever were.)

Also, on another vehicle I am just now replacing a set of Michelin LTX M/S2's that have been fabulous in the rain, also snow, wet and dry. So not everything that Michelin makes is as bad in water as the MXV4.

 

[krzyss]

Originally Posted By: CKN
Really don't understand this thread. I had OEM Michelin MXV4 and they were terrible in rain right off the show room floor.

They would break loose from runoff from the city's overflow water from the green strip in the middle of the street.


I would believe ANYTHING on what they say their wet performance is-because I have owned some and they were terrible.


You blame the car manufacturer of course.
This is how they speced them.

Krzyś

 

[javacontour]

Originally Posted By: HangFire
Originally Posted By: mightymousetech
So basically, buy [censored] tires you get [censored]. Imagine that.


So I'm scratching my head at this. Why would Michelin do this test? If there is a push to require a new minimum tread depth in the EU, Wouldn't all tire manufacturers profit from such a standard? While I'm sure the pollution figures are close enough, I think it gets down to the ratings push by Michelin at the bottom of the article. I'm sure Michelins would rate above the cheap Asian imports...

Researching I just found this, but it doesn't seem to have the 2016 changes it expected:
http://www.blackcircles.com/general/tyre-labelling/tyre-label

Seems wet tire ratings are already in there. I guess Michelin wants WORN WET tire ratings.


I suspect EU laws require tire makers to recycle those worn tires.

More frequent replacement may actually cost them and the consumer more.

Seems to be a bad use of resources. It takes a certain amount of energy to make a tire. If you make consumers change with 2x as much tread remaining, that's wasted energy.

 

[javacontour]

Also, don't tires have some sort of release agent on them when brand new?

I.E. is it a valid comparison with a brand new tire vs a tire with say a few hundred up to a thousand km/miles on it. Do new tires have a break in period? That can skew the results.

But I do agree with the point. A quality used tire may be better than a poor quality brand new tire.

Edited to add: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=5

 

[d00df00d]

Originally Posted By: mightymousetech
Originally Posted By: andyd
1/16 remaining tread definitely limits the safe speed that a car can travel in the wet. . AKMHIK. I bought a 528e project with well worn Coopers on it. They passed MA state inspection, barely. I could drift at 30 mph on a heavy dew, let alone rain. Dry they were fine and they wore like iron.


That is the whole point of this article. Buy good tires and they are better in the wet at 1/16" than many cheaper tires at full tread depth.

I would rather be on zero tread depth slicks in damp weather than a cheap tire.

Having driven on good tires at 1/16", and cheaper tires, this is exactly my experience.

 

[d00df00d]

Originally Posted By: Quattro Pete
Originally Posted By: HangFire
Originally Posted By: mightymousetech
So basically, buy [censored] tires you get [censored]. Imagine that.


So I'm scratching my head at this. Why would Michelin do this test? If there is a push to require a new minimum tread depth in the EU, Wouldn't all tire manufacturers profit from such a standard?

Michelin would lose their competitive differentiation if minimum tread depth was increased.

Right now, Michelin can say that their tires offer better performance at 1.6mm tread vs competitors, so their marketing dept will spin it that you get more useful life out of their tires, and therefore their tires are more cost effective because you can run them until they are almost bald.

But if the minimum tread depth is increased to 3mm, then Michelin's advantage disappears because drivers will be required to replace their tires early. At 3mm, most tires still perform well enough. But at 1.6mm, only Michelin tires perform well, or so they claim.


Maybe, but there are technical reasons as well.

Tires with tall tread blocks kind of suck. Yeah, they resist hydroplaning. But they squirm, so they feel terrible to drive on and lose a lot of grip with high loading. And they don't necessarily grip any better below hydroplaning speeds.

They also lose more diameter from new to bald. That means your speedo and anything that depends on wheel speed sensors (ABS, stability control, etc.) have to work with wider tolerances, which decreases their potential effectiveness. It also means that anything about the car that causes the tires to wear at different rates will have an exaggerated effect, which has implications for those systems as well as drivetrain wear and directional stability. They have to be religiously rotated front-to-back AND side-to-side, which makes it that much harder to have staggered fitments and directional treads.

 

[CKN]

Originally Posted By: krzyss
Originally Posted By: CKN
Really don't understand this thread. I had OEM Michelin MXV4 and they were terrible in rain right off the show room floor.

They would break loose from runoff from the city's overflow water from the green strip in the middle of the street.


I would believe ANYTHING on what they say their wet performance is-because I have owned some and they were terrible.


You blame the car manufacturer of course.
This is how they speced them.

Krzyś


Maybe true. Then it's a business decision on Michelin's part. In my case they were down right dangerous and I wanted nothing further to do with the brand. S0- if they were "spec'ed by (in this case) by Honda-and they were that marginal in wet conditions-IMHO Michelin should have walked away from the order. And this was on a top-of-the-line Accord-not a cheap automobile!