Performance of Winter Tires on Wet Asphalt

[SubLGT]

https://www.vti.se/en/news/winter-tyres-small-differences-in-grip-on-wet-asphalt/

Quote:
...Researchers at the Swedish Road and Transport Research Institute (VTI) have studied how grip on wet asphalt under winter conditions deteriorates with the age and wear of different types of winter tyres.

“We focused in particular on comparing studded and non-studded winter tyres in the testing. We found that the braking and steering performance of studded tyres and Nordic-type tyres on snow-free ground is practically the same for both new and used tyres”, said VTI researcher Mattias Hjort.

The winter tyres were divided into three main categories: studded tyres, non-studded tyres of Nordic type, and non-studded winter tyres of Central European type. A smaller group of summer tyres was tested for the purpose of comparison, and both premium and budget tyres were included in the tests.

“When it comes to new tyres, the Central European-type tyres perform roughly 10–13% better than do the other two types of winter tyres. This pertains to both braking and steering”, said Hjort.

In the case of the studded and Nordic-type tyres, there was practically no difference in braking performance between new and worn tyres.

Both the Nordic and Central European types of winter tyres clearly exhibited a greater range of braking performance than did the studded tyres, this being true of both new and worn tyres. In contrast, the steering performance did not differ between the tyre types.

In principle, the summer tyres perform as well as or better than the Central European-type winter tyres, both when new and when worn.

“However, we must point out that, despite this, it is not appropriate to use summer tyres at low temperatures, as their performance becomes markedly worse than that of winter tyres when ice forms. An earlier VTI study found that the Central European-type winter tyres performed markedly worse than did studded tyres or Nordic-type winter tyres on ice and snow”, said Hjort.

About the study A total of 84 tyres were tested, i.e., 31 brand new tyres and 53 used ones. The tyres were tested on a wet salted asphalt road at zero degrees Centigrade...


Once again we see that summer tires (European versions) have traction on wet pavement equal to (or better than) winter tires, even at 0 degC.

 

[SubLGT]

VTI also has a test from 2015, of ice and snow grip for new and worn tires, available for download. But the test is written in Swedish.

https://www.vti.se/en/Publications/Publi...-winter-_878116

Quote:
This study has measured ice and snow grip for used and new winter tyres, with the purpose to investigate how the road grip on ice and snow for different types of winter tyres degrade by age and degree of wear. In total, 77 tyres have been tested, of which 27 were completely new while 50 were used. The tyres have been tested on smooth ice and packed snow. The results show that with respect to ice grip, the studded tyres have a larger performance decrease when worn, than the unstudded winter tyres. However, the ice grip of worn studded tyres were still clearly superior to that of worn unstudded tyres. The used unstudded tyres of European type have in general a very poor ice grip, on level with two summer tyres that were also tested. On snow, the unstudded winter tyres of Nordic type in general have a slightly better grip than the studded tyres, while the unstudded tyres of European type performs worse. The snow grip for the used tyres is significantly worse than used tyres of the other two types. The study also shows that the premium tyres in general have better ice and snow performance compared to the budget tyres, for both new and used tyres.

 

[krzyss]

Originally Posted By: SubLGT
https://www.vti.se/en/news/winter-tyres-small-differences-in-grip-on-wet-asphalt/

Once again we see that summer tires (European versions) have traction on wet pavement equal to (or better than) winter tires, even at 0 degC.


I think this is the translation ring:

studded tyres - studded tires
non-studded tyres of Nordic type - studless winter
non-studded winter tyres of Central European - performance winter

It shows what we expected before. Performance winters are the best winter tires in dry and wet.

Krzys

 

[finmile]

Originally Posted By: krzyss
It shows what we expected before. Performance winters are the best winter tires in dry and wet.


Correct. And nothing beats studded winter tires on ice.

 

[krzyss]

After reading the article it seems that they debunk one thing:

"In principle, the summer tyres perform as well as or better than the Central European-type winter tyres, both when new and when worn."

That means that on cold pavement, dry or wet, summer tires are no worse than performance winters - they are as good or better.
Of course summer tires go crazy with any ice or snow.

In short - on nice, dry winter day summer tires are not bad but do not drive when snow flakes are falling (or freezing rain).

Krzys

 

[d00df00d]

Also, probably a bad idea not to use winter tires below the glass point of the rubber.

 

[SubLGT]

From the abstract in the downloaded report:

Quote:
The new [central] European winter tyres perform 10–13 per cent better than the two other types of winter tyres on wet asphalt in the current weather conditions. For the worn tyres, the advantage of the [central] European tyres is smaller, 5–7 per cent better than the other two types of winter tyres. The summer tyres perform as good as, or better, than the European winter tyres. This applies to both new and worn tyres.

 

[SubLGT]

Originally Posted By: krzyss
...That means that on cold pavement, dry or wet, summer tires are no worse than performance winters - they are as good or better….Krzys


Aren't European market "summer" tires (especially in northern Europe) very similar to North American all season tires? That is my impression, but I have not lived over there.

 

[krzyss]

I have not lived in Poland for 22 years but I do not think that summers have M+S markings.
When visiting I never needed to buy tires but I did notice a lot of cars on winter tires (mostly winter performance) in summer.

Last summer I was renting Volvo V60 on TS830. It was +30C.
Luckily it was dry.

Krzys

 

[Quattro Pete]

Originally Posted By: SubLGT
Aren't European market "summer" tires (especially in northern Europe) very similar to North American all season tires? That is my impression, but I have not lived over there.

Yes and no. I guess the selection of summer tires over there is much greater and a lot of them are not particularly high performance varieties. They are just general grand touring tires that people run for 3 seasons.

Here in the US, when you mention "summer tires" people typically think "high performance."

 

[69GTX]

Originally Posted By: d00df00d
Also, probably a bad idea not to use winter tires below the glass point of the rubber.


Where do you find this temperature? 40-45 degF. has often been tossed around as the lower temp limit for summer performance tires (Max, UHP). But, that likely varies quite a bit from mfg to mfg and the grip/tread wear rating of the tire.

"If ambient temperatures drop to near- or below-freezing, driving or rolling a vehicle equipped with summer performance tires risks the possibility of tread compound cracking. Tread compound cracking is a permanent condition that requires the tires to be replaced. The other condition that can be caused by running summer performance tires in cold temperatures is the possibility of chipping away the edges of the tread blocks."....from Tire Rack Tech.

 

[69GTX]

Consumer reports and GM recommendations on summer performance tires

 

[d00df00d]

Originally Posted By: 69GTX
Originally Posted By: d00df00d
Also, probably a bad idea not to use winter tires below the glass point of the rubber.


Where do you find this temperature? 40-45 degF. has often been tossed around as the lower temp limit for summer performance tires (Max, UHP). But, that likely varies quite a bit from mfg to mfg and the grip/tread wear rating of the tire.

"If ambient temperatures drop to near- or below-freezing, driving or rolling a vehicle equipped with summer performance tires risks the possibility of tread compound cracking. Tread compound cracking is a permanent condition that requires the tires to be replaced. The other condition that can be caused by running summer performance tires in cold temperatures is the possibility of chipping away the edges of the tread blocks."....from Tire Rack Tech.

Yeah, good call. I wasn't really thinking with that post; it's technically true, but useless in practice because the glass point is basically impossible to find exactly.

Personally, I'd use the manufacturer's guidance as a starting point. E.g., if it's 32º out, I might find it in myself to gamble with a tire that lists 35º as a minimum temp, but not with a tire that lists 45º.

 

[d00df00d]

Originally Posted By: 69GTX
Consumer reports and GM recommendations on summer performance tires

Nice! Just gotta find the OE tires for the cars listed, and we'll have some good guidelines for those. :]

 

[69GTX]

Originally Posted By: d00df00d
Originally Posted By: 69GTX
Consumer reports and GM recommendations on summer performance tires

Nice! Just gotta find the OE tires for the cars listed, and we'll have some good guidelines for those. :]


Did a lot more reading on that subject and I'd place only the Extreme/Max and a few select UHP summer tires in that 40-45 deg F group. Even so, tires like the PSS may do quite well down to 25-35 deg F. Summer tires on clean and dry roads should perform ok. I did run across 20 deg F as being a danger point for Extreme/Maz perf summer tires for storage. Any colder and you shouldn't even move them until they've warmed back up to 40 deg again for 24 hrs.

Ice, frost, and snow in even tiny amounts are the biggest problems with summer tires above 25 deg F. I've have my Good Year Eagle F1's and BFG sport Comp 2's out in 30-35 deg F weather with never an issue. But, I never go out if there's moisture or ice. Those tires have 300+ tread wear rating, not the 100-200 ratings often seen on extreme/max summer tires. I think the tire mfg's and distributors are using the 40-50 deg F levels for liability issues as well as to sell more tires. Europe requires A/S tires once temps are under 45 degF.

 

[edyvw]

Originally Posted By: krzyss
I have not lived in Poland for 22 years but I do not think that summers have M+S markings.
When visiting I never needed to buy tires but I did notice a lot of cars on winter tires (mostly winter performance) in summer.

Last summer I was renting Volvo V60 on TS830. It was +30C.
Luckily it was dry.

Krzys

No they do not. I have never seen Euro summer tire with M+S marking, nor I ever had summer tire there that was resembling North American All Season tire.

 

[edyvw]

Originally Posted By: Quattro Pete
Originally Posted By: SubLGT
Aren't European market "summer" tires (especially in northern Europe) very similar to North American all season tires? That is my impression, but I have not lived over there.

Yes and no. I guess the selection of summer tires over there is much greater and a lot of them are not particularly high performance varieties. They are just general grand touring tires that people run for 3 seasons.

Here in the US, when you mention "summer tires" people typically think "high performance."

^This!
In Europe you have summer tires that are made for all type of cars and I have NEVER seen car coming when new with all season tires.
When I lived there I was making 40-50K a year due to work. Had all kinds of tires, and only once saw al season tire available to buy.
What people do there is they drive summer tires mid April or may to end of october, mid november. After that, in many European countries 15 of november is when you legally have to have winter tire.

 

[SubLGT]

What would probably be marketed in the USA as "all weather" tires seem to be marketed in the European market as "all season" tires. Tires such as the Michelin Cross Climate, the Goodyear Vector 4Season, the Nokian WeatherProof, etc. Many of them certainly have much more aggressive tread designs than a typical American market all season tire. Are they replacing European summer tires for 3 season use? Or being used year round?

http://www.tyrereviews.co.uk/Article/2016-ADAC-All-Season-Tyre-Test.htm
http://www.tyrereviews.co.uk/Article/2016-AutoBild-All-Season-Tyre-Test.htm
http://www.tyrereviews.co.uk/Article/2016-GF-All-Season-Tyre-Test.htm

 

[edyvw]

Originally Posted By: SubLGT
What would probably be marketed in the USA as "all weather" tires seem to be marketed in the European market as "all season" tires. Tires such as the Michelin Cross Climate, the Goodyear Vector 4Season, the Nokian WeatherProof, etc. Many of them certainly have much more aggressive tread designs than a typical American market all season tire. Are they replacing European summer tires for 3 season use? Or being used year round?

http://www.tyrereviews.co.uk/Article/2016-ADAC-All-Season-Tyre-Test.htm
http://www.tyrereviews.co.uk/Article/2016-AutoBild-All-Season-Tyre-Test.htm
http://www.tyrereviews.co.uk/Article/2016-GF-All-Season-Tyre-Test.htm

Nah, that is new attempt to introduce something new. There was a period when several manufacturers tried to introduce all season tires (particularly Hankook and GY) but it never gained traction. I am not saying that those tires are not sold in some quantity, but really not best option for European summers and HWY's and speeds there.
Maybe there is an attempt to sell them in UK since summers are cool, and winters really not that hard. But in continental Europe, they will be hard sell.

 

[krzyss]

I saw a recent test of Goodyear 4S and Michelin CrossClimate. I did not pay much attention as they are not: 1) available in the USA 2) not my cup of tea.
However:
GY are winter tire turned into all weather (similar to Nokian WR).
Michelin are summer tires turned into all weather (that is unique approach).

Both are decent choice for people in cities (the flatter the better) but GY is better in winter conditions and Michelin in dry, wet.
Michelin has decent traction for braking and accelerating but not for turning.
If my memory works.

People in cities are more likely to suffer from lack of space to store second set of wheels/tires ("tire hotel" - storing at the seller still costs money).

I think this is English version of German original that I read in Polish ;-)

http://www.tyrereviews.co.uk/Article/2016-AutoBild-All-Season-Tyre-Test.htm

Krzys