2010 Winter Tire Tests

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^ Are you a native speaker?

 

But thank you for pointing that out! It's a subtle difference that the faster/more careless reader (who, me? no!? ) may not necessarily catch.

 

 

I'm native Siberian

Have been living in Canada for 6 years though.

 

BTW, back there we prefer studded tires. Nokian Hakkapellitta 2/4/5/7 is a perennial favorite.

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Yes, the temperature effect is something I wish the testers would investigate more...

Here is another article in Russian: http://www.zr.ru/a/16906/

 

The graphs are quite self-explanatory.

 

In short:

 

-19C an colder: studless tires are better on ice, because the ice surface may be too hard for studs to bite effectively.

 

-13C: studded and studless tires are more or less similar.

 

-5C: studded average braking distance (from 50km/h down to 5 km/h) 29 m, studless ~55 m.

 

0C: studded 33 m, studless ~82 m.

[TSiWRX]

^ Most interesting! Thank you!

 

I wonder - given the large difference between the ContiVikingContact and the Xi2-North, at -19 deg. C....does this logically lead one to think that tire compounding makes for the difference, here?

 

In more recent Auto Review tests (error, please correct me on this - and/or expand, given your language capabilities ), it was mentioned that in many cases, the clear dry/wet pavement performance of the studded tires often bettered the "Studless Ice & Snow" tires due to the latter's compounding perhaps being too soft. I wonder, given the seemingly disparate ends of these two aims, if such a balance is possible?

 

Also, does vehicle weight and/or weight-distribution matter?

[error]

Studless tires use very soft rubber compounds and fine tread patterns with numerous micro-edges that bite into the surface.

 

Studded tires are usually stiffer because they have to support the studs, and have larger tread blocks. Recent models use dual compound rubber + very soft rubber underneath the studs (so the studs can "retract" on hard pavement to some extent) + studs themselves have more and more complex geometry and in some cases are glued-in.

 

There are several important implications:

- Stiffer rubber on studded tires gives them better handling (at least, theoretically);

- Tires that have been studded at a local store are no match to factory-studded rubber. Always check that. Stores usually do not have access to the proprietary fancy octagon/diamond multi-flange studs whose design Nokian and Continental have been carefully refining for years, nor they have equipment and skills to do that properly.

- "Studdable" tires are nonsense. They do not have soft rubber and tread patterns that would work well on ice, and no studs either.

 

As for your question regarding Conti and Michelins - both are studded models. I'm not quite sure how they did the experiments (proper randomization, number of replicates, ANOVA design, etc. ), but I would carefully guess that [this particular model] Conti had better stud design than Michelins. Studless tires used were Nokian Hakka R (I just ordered myself a set), Bridgestone WS 60 (used for the last 3 winters, very satisfied, except for braking in slush), and Michelin Xi2.

 

If you drive a lot on snow/ice covered back roads AND studded tires are legal in your area, Nokian Hakka 7 seems to be a logical choice. IMO, studded tires last longer too. For normal city driving, the difference between the top 3-5 models would probably be statistically negligible.

[outahere]

Here is another article in Russian: http://www.zr.ru/a/16906/

 

The graphs are quite self-explanatory.

 

In short:

 

-19C an colder: studless tires are better on ice, because the ice surface may be too hard for studs to bite effectively.

 

-13C: studded and studless tires are more or less similar.

 

-5C: studded average braking distance (from 50km/h down to 5 km/h) 29 m, studless ~55 m.

 

0C: studded 33 m, studless ~82 m.

 

Very interesting indeed. At -19C (-2.2F) the best studless tire requires 9.8m less to stop on ice than the worst studded tire. A significant advantage!

 

At -1C (30.2F) the best studded tire requires 58.3m less to stop on ice than the worst studless tire. A monumental advantage!

[outahere]

Here is another article in Russian: http://www.zr.ru/a/16906/

 

The graphs are quite self-explanatory.............

 

In the line graph the Nokian R is shown twice. What is the difference between these 2 Nokians? Tread depth?

[TSiWRX]

^ Ooooh, good eye!

 

 

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- Tires that have been studded at a local store are no match to factory-studded rubber. Always check that. Stores usually do not have access to the proprietary fancy octagon/diamond multi-flange studs whose design Nokian and Continental have been carefully refining for years, nor they have equipment and skills to do that properly.

 

Indeed - this is a problem here in the States, currently.

 

 

As for your question regarding Conti and Michelins - both are studded models. I'm not quite sure how they did the experiments (proper randomization, number of replicates, ANOVA design, etc. ), but I would carefully guess that [this particular model] Conti had better stud design than Michelins.

^ Now that was something I had not thought of. Very reasonable/logical.

 

 

If you drive a lot on snow/ice covered back roads AND studded tires are legal in your area, Nokian Hakka 7 seems to be a logical choice. IMO, studded tires last longer too. For normal city driving, the difference between the top 3-5 models would probably be statistically negligible.

^ I truly entertained going after the studded Hakka 7s - the price was a bit of a reach for me, given that I had an unexpected trip come up, so I decided to go with a set of studded Pirelli Winter Carvings.

 

Here in NE-Ohio, legally speaking, studded tires are allowed from the first day of November through the 15th of the following April, but for me, I'm going to be using them only from about mid-late December to mid-February or so (and again later, if there's a big storm predicted): rotating in their place my old set of 3Ds (I'm actually getting ready to put them on this weekend; and they'll stay on from mid-February through about the first week or two of May.

 

Our main roadways are typically very nicely groomed during the winters: it's only true storms that catches the local municipalities out-of-sorts (the ones with more money are virtually never that bad, though). However, in the days after, freezing temperatures often turn the intersections between less-traveled side-streets to major thoroughfares into a dangerous no-man's-land of sheet black-ice.

 

Even then, truly, like my friends have said, I'm probably likely to gain enjoyment of my studded set only minutes per winter season. :lol: It would've been more logical for me to have stuck with a set of "Studless Ice & Snows," but I couldn't help wanting a set of studded tires, since I've never tried them before.

 

Very interesting indeed. At -19C (-2.2F) the best studless tire requires 9.8m less to stop on ice than the worst studded tire. A significant advantage!

 

At -1C (30.2F) the best studded tire requires 58.3m less to stop on ice than the worst studless tire. A monumental advantage!

 

^ I think that based on the data, it would be imperative to know the precise weaknesses and strengths of the types of tires you're using, when facing a winter storm and its fallout.

 

It seems that, still, no one tire is able to do it all - where are those Q-Tire people?

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In the line graph the Nokian R is shown twice. What is the difference between these 2 Nokians? Tread depth?

Nokians were unstable on ice: every attempt was better than the previous until after 5-6th run when the results stabilized. The authors think that snow crystals may stick to the Nokians' porous rubber (while driving to the rink) and work like ball bearings on ice. After several runs on pure ice treads would clear and results stabilize. That's why there are two graphs for Hakka R.

 

They say, it never occurred to Finnish engineers, because they normally keep the tires in a heated garage between tests and (obviously) mount them in a heated shop. Warmer tires would clear snow a lot better. In the "Za rulem" tests, all tires were kept at the ambient temperature, hence the difference.

 

They contacted Nokian engineers and since April 2008 all Hakka R and Hakka SUV made in Russia (we have Nokian factory there) are manufactured using highly polished press-forms that leave the vertical surfaces in major sipes (is it the right word?) very smooth. The follow-up tests indicated that the problem has been eliminated.

[TSiWRX]

^ Very, very interesting (yes, sipes is correct)! Thank you!

[krzyss]

"that leave the vertical surfaces in major sipes (is it the right word?) very smooth"

 

So the snow does not stick to rubber in voids and is ejected during rotation, I presume.

Correct?

 

Krzys

[error]

Yes, that was my understanding.

[outahere]

Something to keep in mind when looking at winter tire test results:

 

A multitude of variables will affect [test] results, including the following:

􏰀 initial speed (for braking tests)

􏰀 tire type (studded, non-studded, studless)

􏰀 number of studded tires (two or four)

􏰀 vehicle type (automobile, truck, SUV)

􏰀 vehicle drive configuration (front-wheel drive, rear-wheel drive, four-wheel

drive)

􏰀 vehicle weight distribution

􏰀 brake system type (ABS or non-ABS)

􏰀 roadway pavement type and condition

􏰀 roadway surface condition (dry, wet, loose snow, packed snow, smooth ice, stud-

roughened ice)

􏰀 temperature (above freezing, near freezing, well below freezing).

 

Above text is from:

"AN OVERVIEW OF STUDDED AND STUDLESS TIRE TRACTION AND SAFETY"

Washington State Transportation Center (TRAC) 2002

[TSiWRX]

^ Add stability control to the mix?

[krzyss]

Stability control was not that popular is 2002.

 

Krzys

[TSiWRX]

^ Good point - I'm in a time-warp.

[outahere]

The Swedish magazine Aftonbladet has released their test results of 28 winter tires: 14 studded, 8 non-studded, and 6 performance winters.

 

http://www.aftonbladet.se/bil/article7936749.ab

 

Unfortunately, as far as I can tell, the report is only available to paid subscribers.

[outahere]

Teknikensvarld tested 15 winter tires, a mix of studded, non-studded, and performance.

As far as I can tell, the report is only available to paid subscribers.

 

http://www.teknikensvarld.se/documents/dacktester/vinterdackstest/2010-vinterdacktest-15-st/index.xml

 

For whatever reason, Google Translate does not want to translate the above page.

[TSiWRX]

Google Translate is refusing to translate either documents, on my old desktop here at home (I've noticed that on this old computer, the documents tend to revert back to their native language sooner than when I run the translator on a faster computer/connection ???).

[outahere]

Another test of studded and non-studded. From Russia, with love.

 

http://www.autoreview.ru/_archive/section/detail.php?ELEMENT_ID=73796&SECTION_ID=2173

 

Among the non-studded, they rated the Goodyear Ultra Grip Ice + as the best performer. Goodyear has not been a top performer in the past, but it looks like they are getting serious in this market. In the USA, we have the Goodyear Ultra Grip Ice, but not the "+" version. Maybe next year?

 

Its strengths:

• Longitudinal grip on ice and snow best in the class of non-studded tires

• High resistance to slushplaning

• grip on wet and dry asphalt

[TSiWRX]

^ Oh man, bro, you're losin' it!

 

Good stuff. So which tests happen at 'test world' in Finland? I was just reading some fresh test results from those, in Russian though. Hakka 7 came out first among studded, and Goodyear Ultra Grip Ice+ some how edged over both some Conti's, Hakka Rs and Xi2.

 

 

Senility strikes early!

[outahere]

I thought the Russian test had been posted before, but I was too lazy to check.

 

Maybe Krzyss can post a link to the Polish tests of winter tires? Or has he already done that? I can't remember.

[outahere]

If you want to read a more academic approach to winter tire testing, consider these reports from the mid 1990s:

 

 

 

 

"Lu, J. "Vehicle Traction Performance on Snow and Icy Surfaces", in Transportation Research Record 1536, 1996, pp. 82 - 89"

 

Abstract:

Snow and ice have been considered the main factors that contribute to reduced vehicle traction forces and potential traffic accidents during winter. To increase a vehicle's traction on snow and icy surfaces, studded and nonstudded winter tires have been used in cold regions. However, the use of studded tires causes significant pavement damage, such as accelerated pavement rutting and pavement marking damage. Since spring 1994, the Alaska Department of Transportation and Public Facilities has asked the Transportation Research Center at the University of Alaska, Fairbanks to conduct a series of research studies related to vehicle traction performance on snow and icy surfaces in Alaska. One of the studies conducted in 1995 is summarized. The main objectives of the study were to evaluate (a) traction performance of used winter tires on roadways, (b) traction performance comparison of lightweight studded tires with other winter tires, © traction performance of vehicles with two front studded tires, and (d) effects of vehicle type on traction performance. Field tests were conducted on traveled roadways and in parking lots. The main traction performance measurements included stopping distances, maximum stopping deceleration forces, time necessary to reach a certain speed, and maximum starting acceleration forces.

 

 

 

"Lu, J., D. Junge, and D. Esch, "Evaluation of Winter Vehicle Traction Forces with Different Types of Tires", in Transportation Research Record 1501, 1995, pp. 22-30"

 

Abstract:

Studded tires have been used during winter to increase vehicle traction force for reasons of safety. Past experience and factual data have shown that the problems of accelerated pavement wear and airborne dust have been caused by the use of studded tires. The use of studded tires has been prohibited in some countries and in some states in the United States. Recently, the Bridgestone Tire Company designed and examined a new type of tire, called the Blizzak, to improve winter vehicle traction and minimize pavement wear. To adopt this new type of tire in Alaska, the Alaska Department of Transportation and Public Facilities conducted a preliminary field study to compare the new tires with the studded tires in terms of stopping distance on packed snow and icy surfaces in Fairbanks and Anchorage in January 1994. More comparative tests of the Blizzaks, studded tires, and all-season tires were conducted in March 1994 by the University of Alaska in Fairbanks and Anchorage. The vehicles used in these tests were mid-size front-wheel-drive cars, large rear-wheel-drive cars, and half-ton full-size rear-wheel-drive pickup trucks. Field tests included 40.3-km/hr (25-mph) stopping distances, starting traction and times to reach 40.3 km/hr (25 mph), maximum cornering speeds on short-radius curves typical of intersections, and hill climbing ability. From field test results, it was concluded that Blizzaks may be used during winter to replace studded tires in Alaska.

 

 

"Lu, J., Winter Vehicle Traction and Controlability Performance, Final Report for Alaska DOT Project, Report No. INE/TRC 95.04, Transportation Research Center, University of Alaska Fairbanks, 1995"

 

"Lu, J., Studded Tire Performance and Safety, Final Report for Alaska DOT Project, Report No. INE/TRC 94.06, Transportation Research Center, University of Alaska Fairbanks, 1994"

 

"Lu, J., Junge, D., and Esch, D., Winter Tire Traction Evaluation, Final Report for Alaska DOT Project, Report No. INE/TRC 94.03, Transportation Research Center, University of Alaska Fairbanks, 1994"

[TSiWRX]

^ Good-grief.... 15-year old data! Don't they have something newer?

 

Not that I won't try to somehow get my paws on some reprints, though. Thankyee!

 

 

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I thought the Russian test had been posted before, but I was too lazy to check.

 

^

 

Maybe Krzyss can post a link to the Polish tests of winter tires? Or has he already done that? I can't remember.

 

^ You know, I can't remember, either...... Something makes me want to say that he has....

[outahere]

^ Good-grief.... 15-year old data! Don't they have something newer?.........

 

For a fee, these newer reports are available from the Swedish National Road and Traffic Institute (VTI):

 

2004-09-10 Friction on ice for new and used winter tyres

 

2004-06-28 The friction on wet smooth ice for new and used winter tyres. An investigation concerning the influence of age, tread depth, tread rubber hardness, stud protrusion and stud force.

 

2003-11-11 The correlation between grip on rough ice of winter tyres and their age, tread depth and tread rubber hardness

 

2003-09-09 The friction on smooth ice for new and used winter tyres

 

2001-10-23 Comparative test of the effect on wet ice friction of adding a special aggregate in the tread rubber of a retreaded M+S tyre type

 

http://www.vti.se/default____2782.aspx

 

 

You may also be able to find more up to date research reports here:

http://www.nordicroads.com/website/index.asp

 

 

And when you win the lottery, you can commission your own winter tire tests in Ivalo, Finland:

http://www.testworld.fi/

[TSiWRX]

^ I'm actually able to view the English-language summaries (the website notes that most articles contain an English summary, but most fulltext is only available in Swedish) for free. I was also able to download the first article (2004-09-10 Friction on ice for new and used winter tyres) in .pdf format, for free. I haven't checked any of the others, though.

 

Actually, even that first article has helped in correcting my apparently erroneous thinking about tire-age presenting to be a factor!

 

I've gotta sit down to do more reading.....

 

 

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And when you win the lottery, you can commission your own winter tire tests in Ivalo, Finland:

http://www.testworld.fi/

 

Ah, winter wonderland.

 

And they thought Michael Jackson was weird.