Anyone planning on trying out the Blizzak WS 70?

http://image.motortrend.com/f/auto-news/winter-resort-mastering-the-snow-with-bridgestones-new-blizzak-ws-70/32187336+w750/blizzak-ws-70-profile.jpg

The tread pattern certainly looks impressive, and here are the bells and whistles:

--NanoPro-Tech with RC Polymer

Optimizes snow and ice performance by controlling interactions of polymer, filler, and rubber chemicals at the molecular level

--New 3-D Sipe

Improves ice, dry and wet performance by enhancing block stiffness and contact area

--Optimized Tread Width

Helps achieve better snow and slush performance

--Four Main Grooves with Deep Tread Depth

Channel snow, slush, and water away from the contact area

--New Multicell Compound

Improves snow, ice, and wet performance

In many respects, the new WS70 is a deluxe version of the current WS60. Familiar technologies abound, such as the NanoPro-Tech rubber compound, which looks akin to DNA chains on the Powerpoint presentation. This proprietary formula is able to provide the proper mix of high cis butadiene rubber for cold weather flexibility, and silica for wet surfaces and improved rolling resistance. There is improved stiffness to the compound in warmer temperatures, removing the ’squirmy’ feeling that some winter tires exhibit on warm pavement. As most Canadians know, winter conditions, and temperatures, are subject to ever-increasing variances of extremes. (Thanks again, global warming.)

http://www.canadiandriver.com/galleries/2010/thumbs/vrt-7479-blizzak-ws70_mc_001-7479.jpg

Bridgestone WS 70 winter tire . Click image to enlarge Water continues to be the enemy of traction and braking on ice. Removing that thin film of water is the job of Bridgestone’s Tube Multicell compound. As the tire wears, microscopic tubes are revealed, which wick away water from the contact patch, in addition to providing thousands of biting edges. For the WS70, the compound now includes metallic bite particles. Don’t worry; it’s not the incessant drone of studded tires of old. The particles ’scratch’ the surface of the ice, assisting with grip improvements. The tread width has been optimized, favoring elongation over width. It’s a plus for snow and slush. Four main grooves appear, up from three on the WS60. Why should your tires be so groovy? Simple; snow sticks best to snow. The more snow your tire can hold, the more grip you’ll achieve on snowy surfaces. Three-dimensional siping optimizes the tread block stiffness, as well as the contact area. Within the sipes are rubbery support bar elements, which assist in keeping the sipe gaps open for swallowing snow, and revealing more biting edges as the tire turns.

 

Instead of a leisurely street test, the Bridgestone team’s first point of demonstration call was an indoor ice rink. Toyota Camry testers were equipped with the Bridgestone WS70s, and Michelin’s X-Ice Xi2s. (This was accompanied with the usual auto scribe murmurs of ‘Where’s all the other tires?’) As expected, the Bridgestones trounced the Michelins in stopping tests, in some cases stopping as early as a sub-compact car length before the Michelins ceased to roll. Of particular note was a stopping test conducted with the WS70’s on one side of the car, with the Xi2’s on the other. The Camry didn’t rip itself in half, though the expected slide of the car simply drove home the WS70’s performance.

 

http://www.canadiandriver.com/galleries/2010/thumbs/mdm-7477-blizzak-ws70_mc_004-7477.jpg

Bridgestone WS 70 winter tire . Click image to enlarge About 15 minutes outside of town is a purpose-built track designed by Mother Nature. The rolling hillsides that make up the Bridgestone Winter Driving School testbed are nothing more than well-packed snow, expertly groomed, and watered to icy perfection. There are zero traction elements added. This is where you quickly learn the need to scrub off speed as you enter a corner. You can make it through most, with massive amounts of understeer, and the Vehicle Stability Control in full Bleep. The instructor base does its best to make sure that never happens, enforcing massive speed dumps before cornering, and refining the skill of understeer recovery. As much as it will make your Brain shout ‘Does Not Compute’, straightening the wheel in an understeer situation allows the tires to renew their bite, allowing you to exit the mess with minimal facial redness, or airbag deployment. As with the ice rink, the WS70’s on the test Camrys trumped the Xi2-equipped versions, again.

 

A secondary track was geared to oversteer recovery, with Toyota 4Runners. Going head-to-head were Bridgestone’s SUV-specific DM-V1, and the Goodyear Wrangler SilentArmor skin. According to Bridgestone, Goodyear tags this tire with the mountain snowflake symbol, (the identifier for a snow and ice-specific tire) advising that a product in the Dueler line has a similar make-up, though it is not tagged with the flake, since it is at the low end of the traction requirements. Whatever the claims, the Bridgestones, (wait for it) exhibited traction and braking advantages over an admittedly inferior product – a product that Bridgestone brands as an all-season tire.

 

http://www.canadiandriver.com/galleries/2010/thumbs/mdm-7480-blizzak-ws70_mc_002-7480.jpg

Bridgestone WS 70 winter tire . Click image to enlarge But are these test methods a fair analysis? Having tested numerous snow tires, I can appreciate the moxy behind this particular Bridgestone demonstration. As difficult as it may be to arrange, such demonstrations need to add more real-world elements. Few of us will ever drive on such virginal surfaces as ice rinks and snow-packed hills. Different municipalities use varying degrees of traction elements to assist winter braking, which should be included with any winter drive/tire test program. While the tests, both indoor and out, possess merit, a wider field of competitors should be the rule.

 

As one sifts through the tech-speak for any tire, it becomes obvious that the science behind such rubbery blends as NanoPro-Tech is as secret as the Colonel’s blend of eleven herbs and spices. A little polite cajoling was used to determine that the bite particles were metallic, though what metal and to what concentration remains a mystery. As a user of studded tires, this is the feature that piques the interest of this reporter. It almost sounds like Nano-Studs are co-mingling on the tread surface. This could be the game-changer for studless tire technology. The creation of a tire that is about as abrasive on ice as a sheet of 80 grit on balsa wood, without duplicating such fun studded tire moments as skating on wet pavement.

A less informative review at:

http://wot.motortrend.com/6618374/auto-news/winter-resort-mastering-the-snow-with-bridgestones-new-blizzak-ws-70/index.html

And spec sheet from Bridgestone: http://productcat.bridgestonetire.com/exports/pp_1286824.pdf

I think they are an excellent choice, especially if you don't drive a lot of miles during winter. If you drive a lot of miles during winter, the multicell layer may only last 1 or 2 seasons.

Maybe I'm wrong, but don't Bridgestone winter tires just become regular tires when they wear half way? I've been running Nokian RSi snows for 5 years, probably have two seasons left, and they work great. Complaints? Expensive, but I'll gladly pay more to get around safely.

^ That's exactly what outahere means - that with the miles burning through their proprietary layer, which is literally near-magical, that's going to be a problem. The reason why I gambled on the Xi2s two seasons ago was because of this very consideration: I didn't want my wifey to have to deal with the double-bogey loss of both the proprietary top-layer as well as having to suffer with decreased tread-depth.

If you don't put on that many miles (or otherwise can stomach the cost), it's a great way to go, if you want to run studless.

To me, this will be the wildcard gamble for those who are looking at the game this winter. Undoubtedly, the new-last-season Conti's will be pitted against the benchmark Xi2s in this winters tests....

Undoubtedly, the new-last-season Conti's will be pitted against the benchmark Xi2s in this winters tests....

...along with the WS 70, right? The WS 70 might be perfect for me since I drive the bimmer on a limited basis in the winter months. I wonder when the first test results will come out on TR?

^ I honestly don't know if the WS70s will be tested immediately - the Xi2s were not, and neither were the Contis: testing seems to be lagged by at least a half-season (correct me on this, outahere), if not a full one, and that seems to be the trend for all tire genres.

In terms of TireRack testing?

I all honesty, I would weigh *any* of their statements, and remember that they are not as unbiased as they may make out to be.

Look at the NASIOC thread, when they were called-out by outahere, myself, as well as others, regarding their testing of the then two-seasons old WS60, versus the by-then-known-quantity Xi2s: what happened when we pointed out that their results contradicted virtually every other known and respected independent testing authority's, regarding the fact that they picked the WS60s over the Xi2s? ---> they essentially backpedaled. When outahere pressed them about their studded versus "studless ice & snow" conclusions, the same happened.

To say that TireRack has repeatedly favored Bridgestones is close to an understatement. Remember, they're not completely unbiased, and as-such, their findings and opinions should be weighed accordingly.

While I don't doubt that the WS70 will surpass the performance of the Xi2s - it had better, as its most direct competitor as well as what would - just how much this margin may be, and more importantly, where the Contis would come into the picture, that's what I see as the bigger concerns.

My personal opinion is that, in this case, the TireRack review/test of the Contis, sandwiched against the WS60 and LM60, isn't that far off - and that of the Bridgestone, Michelin, and Conti offerings in the "studless ice & snow" segment, the Contis will take the cake for its road-manners, but will give up some performance in terms of wintry-precip. (including ice) capabilities, when compared to the others. Nevertheless, just how much it gives up, quantitatively, is not something that I'd, personally, be willing to put faith on for the TireRack's article.

----

I wanted to come back and add:

If this post reads as if I'm somehow "anti TireRack," that's not my intent, and I do apologize if it came across that way.

I hold TireRack in very high regard, for what they've done and are still trying to do - and also have quite a bit of respect for Luke, whose personal mission, it seems, is to keep us Subaru guys and gals happy.

Rather, what I'm trying to say is simple: that one should not use TireRack's official lines as anything more than just one reference among many, and that what they've said should still be examined critically and be properly debated/discussed - not simply and mindlessly taken as the "by Hoyle" scripture, at face-value.

Similarly, one should realize that the popular vote on their "Surveys" should also not be given more weight than proper. Remember that anyone's vote can and will count, and this extends to the entire spectrum of that Forums' user-base, from experienced drivers with many years/sets of tires under their belt to new drivers with only one or two, from experts to hacks. Want proof? Just look to the early user reviews (sort by date) of the Xi2s. Look at how many users said that these were "the worst winter tires I've ever used" - and look at how quickly that story changed, one season later, when published tests/reviews hailed these tires as the best of the breed.

In regard to TR's winter tire testing, findings on this test-- http://www.tirerack.com/tires/tests/spiderChart.jsp?ttid=122 --have always confused me. In the OBJECTIVE testing the Conti EWC won the ice lap but the WS60 won the ice braking and acceleration by a far greater margin. How can that be explained? I would base my choice between the EWC and the WS60 on those findings alone--if I could only make sense of them!

^ I'm not sure you're reading their chart correctly.....

Ice Handling Lap

This test captured the time required to complete a lap of the .4-mile rough ice course. The test was conducted with the vehicle's stability and traction control switched off. ABS brakes were used for consistency and safety.

Tire Line Percent Versus Reference Bridgestone Blizzak WS60 100.0% Continental ExtremeWinterContact 106.5% Michelin X-Ice Xi2 96.4%

I'm amazed at the technology put into.....tires. Molecular level engineering etc. Wow... Love my WS60s. Car was a beast in the snow last year with them. WS70s must be as good and then some from reading those reviews.

+1 - the technology is amazing.

I'm sure that the WS70s will be an improvement over the WS60s: it simply has to be, if in order to topple the Xi2, alone...otherwise, the untold millions spent in developing that tire won't be justified.

OK, but if you look at the spider chart for that test the Conti has the highest rating for the ice lap time, not WS60.

EDIT: I think the numbers you quoted mean that the higher percentage is better.

^ I'm not sure you're reading their chart correctly.....

 

By this chart, the Xi2s had the lower lap time, with the WS60 second, and the Conti third.

 

 

 

 

OK, but if you look at the spider chart for that test the Conti has the highest rating for the ice lap time, not WS60.

 

EDIT: I think the numbers you quoted mean that the higher percentage is better.

^

You're right, I'm not reading things correctly :

Objective test scores are percentage based, using a popular Studless Ice and Snow tire as the reference (Bridgestone Blizzak WS60 scored as 100%). A score above 100% indicates performance better than the reference tire, while a score below 100% indicates performance below the reference.

You're right - that doesn't make any sense at all, then.

In reading the charts and graphs as I would, things would make more sense - but since they'd noted that, specifically, is NOT the way to read the data, I'm lost, too....

Hmmm, I wonder if there's a way to contact TR to ask them about it? I'll check that out.

EDIT: I just spoke to TR, and Roger in sales agreed it was "an anomaly". I expressed the theory that since EWC is the better handling tire, that could have made the difference in the lap time, even when cornering on ice. He agreed that could explain it.

He also told me that the WS70 was coming in September and they would be doing ice testing then. Snow testing has to wait for there to be snow, so that wouldn't happen until mid-winter.

LMAO at Tirerack. Their practice of presenting the data as "percent versus reference" obfuscates the data. But as I read the ice test data, the Xi2 was the winner of all 3 ice tests. They assign the arbitrary score of 100 to the WS60 to make it appear the winner if you just glance at the numbers.

The Xi2 required 82.3% of the time the WS60 required, to accelerate to a fixed distance on ice.

The Xi2 required 84.9% of the distance the WS60 required, to stop from 10mph on ice.

The Xi2 required 96.4% of the time the WS60 required, to complete a lap on the ice handling course.

Didn't Consumer Reports also find that the Xi2 outperformed the WS60 on ice? (I'm not a CR subscriber, so I don't have a copy of their test report).

Saw this explanation later on the tirerack page:

"A score above 100% indicates performance better than the reference tire, while a score below 100% indicates performance below the reference."

So based on this, the Xi2 performed worse on ice than the WS60!

Tirerack gets a failing grade for data presentation!

LMAO at Tirerack. Their practice of presenting the data as "percent versus reference" obfuscates the data. But as I read the ice test data, the Xi2 was the winner of all 3 ice tests. They assign the arbitrary score of 100 to the WS60 to make it appear the winner if you just glance at the numbers.

 

The Xi2 required 82.3% of the time the WS60 required, to accelerate to a fixed distance on ice.

 

The Xi2 required 84.9% of the distance the WS60 required, to stop from 10mph on ice.

 

The Xi2 required 96.4% of the time the WS60 required, to complete a lap on the ice handling course.

 

 

Didn't Consumer Reports also find that the Xi2 outperformed the WS60 on ice? (I'm not a CR subscriber, so I don't have a copy of their test report).

 

 

Saw this explanation later on the tirerack page:

"A score above 100% indicates performance better than the reference tire, while a score below 100% indicates performance below the reference."

 

So based on this, the Xi2 performed worse on ice than the WS60!

 

Tirerack gets a failing grade for data presentation!

Are you referring to data that is not available on TR's website? If not, where is it? Also, the X-Ice was the only tire to get a full red bullet (top rating) in CR for ice braking. That's all they tested for, they didn't rate for ice acceleration or for handling on the ice lap, which I think is a weakness of CR compared to TR. (I am a subscriber to CR's website, but I couldn't find the article, only the rating table. But I could look again.)

My comments were in reference to this data:

http://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=122

Didn't Consumer Reports also find that the Xi2 outperformed the WS60 on ice? (I'm not a CR subscriber, so I don't have a copy of their test report).

http://www.canadiandriver.com/forum/index.php/topic,64325.0.html

^ I actually stole that from one of your references, on NASIOC.

And remember, that's where TireRack's official stance started waffling - when the two of us, as well as a couple of others, started questioning Luke as to why their data stood contrary to virtually that of all other tests, both domestic and abroad, which compared the WS60 and the Xi2, and found the Bridgestones wanting...

The X-Ice XI2 does very well and occupies the #1 position on our website as well but, where it wins out is with less tread squirm and lower road noise than the WS60. In the end both are excellent choices for winter tires. here's is some other info about the CR tire test article

 

The November 2009 issue of Consumer Reports includes their annual tire test. However it should be noted that while Consumer Reports tire categories are listed as All-Season Tires, Performance All-Season and Winter Tires, their actual rankings have mixed tires from several traditional tire categories.

 

Their all-season tire categories appear to be defined solely by the speed rating (S&T, H or V) of the exact tire tested, which has resulted in mixing passenger, touring and performance tires together. Unfortunately this ultimately compares all of the tires without consideration of their primary intended use, as well as results in some H- and V-speed rated passenger and touring tires finding themselves pitted against competitors they were never intended to face. Additionally, Consumer Reports single winter tire category lumps Q-, R-, S-, T- and H-speed rated Studable Winter, Studless Ice and Snow and Performance Winter tires together, again confusing the categories.

 

It’s also important to remember that the overall scores are weighted to emphasize individual tire capabilities Consumer Reports’ considers as safety-related characteristics, including dry and wet braking, handling and resistance to hydroplaning. Regional characteristics that are only important in selected parts of the country, such as snow and ice traction, are considered a lower priority and receive less weight in the overall scores. General characteristics, such as ride comfort, noise, rolling resistance, tread life and price receive the least emphasis in the overall scores.

 

However considering the time of the year, many drivers are now finalizing their plans for which tires they’ll select to help them make it through this winter. Winter weather often subjects drivers living in America’s Snowbelt to the most challenging road conditions they’ll face all year. Getting stuck in the snow or sliding out of control on ice are situations drivers just don’t want to experience. This leads many Snowbelt drivers to focus on snow and ice traction to select tires that deliver the best traction when road conditions are at their worst.

 

Consumer Reports indicates their ratings are now designed to compare individual performance characteristics of any tire line with all others (indicating all tires were rated on the same scale). Unfortunately the specific tire performance characteristics being rated are not always presented in the same order in the magazine or on the Consumer Reports website. Therefore callers should be advised to make sure they are comparing the named characteristic, rather than simply a column location in the charts.

 

I’ve sorted all of the tires offered by Tire Rack into their traditional categories in the attached spreadsheet. I then took the Consumer Reports ratings (without weighting any of the individual results for importance) and aligned the data so each performance characteristic is presented in the same column. In this format you’ll notice the Consumer Reports rankings and Tire Rack’s tire survey results often show similar trends.

 

Michelin should be commended for having earned the top position of each Consumer Reports tire category rated this year. Perhaps it’s confirmation of why these same Michelin tire lines currently are rated first (or second) in their respective Tire Rack consumer survey categories.

 

 

Consumer Reports Rankings Tire Line Tire Rack Survey Rankings

1st Performance All-Season (V) MI Pilot Exalto A/S 1st High Performance All-Season

1st Performance All-Season (H) MI Primacy MXV4 1st Grand Touring All-Season

1st All-Season Tires (S & T) MI HydroEdge 2nd Passenger All-Season

1st Winter Tires MI X-Ice Xi2 1st Studless Ice and Snow

 

Additionally when the tires are separated into their conventional tire performance categories, some of the other top lines in Consumer Reports rankings also hold high positions in Tire Rack survey results.

 

3rd All-Season Tires (S & T) PI P4 Four Seasons 1st Standard Touring All-Season

2nd Winter Tires GE Altimax Artic 1st Studable Winter

Highlighted for clarity - so, after some "realignment," the Xi2s come out on top, just like it does with all of the other tests from last season? :lol:

Next time I'm wrong about something, I'm gonna tell the wifey that after some "realignment," I came to the same conclusions as she did, and was therefore also completely right. :lol:

OK, in all seriousness:

FWIW, I *don't* expect all tire tests to agree with one another, 100%.

Yes, I do expect at least some semblance of consistency, and perhaps the same "trends," but testing conditions - especially of winter testing - can vary drastically, so I honestly don't expect hand-holding Kumbaya lovin' when I look across the data.

I would have expected TireRack to have better defended their data.

For us scientists, that's what it's all about: making sure that our methods and procedures are sound, and that our conclusions are logical - after that, it's about showing what you did. If someone comes along and proves you wrong, fine - no-one's right all the time, and as our understanding/methods/technology improves, it may well be that your original conclusions are wrong or your original methods not totally proper - but if you've done what you're supposed to do correctly, and you've drawn the logical conclusion, and it is, to the best of your knowledge, honest and proper, then stand by it.

Although I appreciated what Luke said, to shed light on how confusing the CR testing/results were, particularly to the lay reader - and, BTW, that is an opinion shared by MANY enthusiasts, myself among them - I did not like the fact that they essentially caved under the weight of the questioning. I'd liked for them to have simply said "hey, you know what, we stand by our data - and we'd welcome some of you to come out here to observe our testing next winter" or "we're more than willing go to an independent audit of our data."

Why a magical "realignment" was able to correlate their data with that of CR[/b]'s (and virtually every other 2009/10 winter tire test)? That, my friends, doesn't sit well with me, as it defies logic.

For if it is true that this "realigned" data/conclusion - that the Xi2s should come out on-top - is indeed the right conclusion, then what is it, exactly, that would make the TireRack find the Xi2s to be lacking, when compared against the WS60?

-----

Hmmm, I wonder if there's a way to contact TR to ask them about it? I'll check that out.

 

EDIT: I just spoke to TR, and Roger in sales agreed it was "an anomaly". I expressed the theory that since EWC is the better handling tire, that could have made the difference in the lap time, even when cornering on ice. He agreed that could explain it.

Great that you got to speak with someone!!!

OK, wait a second:

He agreed that it's "an anomaly," but what does that mean, exactly?

Does it mean that what they said, regarding the higher percentage values being "better," is what it should be, and that the conclusion should therefore be that the Contis would have "won" the entire test?

Or does it mean that their method of assessing "percentage of reference value" is the anomaly (i.e. that, instead, it's the way that outahere and I had interpreted it, that a lower percentage should reflect lower lap-time/shorter stopping distance/faster acceleration-to-distance [less time elapsed-to-distance]), and that, instead, the Michelins should have "won?"

...........Or does it mean that their method of assessing "percentage of reference value" is the anomaly (i.e. that, instead, it's the way that outahere and I had interpreted it, that a lower percentage should reflect lower lap-time/shorter stopping distance/faster acceleration-to-distance [less time elapsed-to-distance]), and that, instead, the Michelins should have "won?"

What TR does is compute the % difference between the two times or two distances, then subtract that positive or negative number from 100 to get the "percent versus reference". It would be less ambiguous if they called this number a relative ranking, instead of calling it a "percent versus reference".

So in their scheme, the higher the "percent versus reference" number is, the better the tire performance.

It's a little clearer if you look at the data here:

http://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=125

Great that you got to speak with someone!!!

 

OK, wait a second:

 

He agreed that it's "an anomaly," but what does that mean, exactly?

 

Does it mean that what they said, regarding the higher percentage values being "better," is what it should be, and that the conclusion should therefore be that the Contis would have "won" the entire test?

 

Or does it mean that their method of assessing "percentage of reference value" is the anomaly (i.e. that, instead, it's the way that outahere and I had interpreted it, that a lower percentage should reflect lower lap-time/shorter stopping distance/faster acceleration-to-distance [less time elapsed-to-distance]), and that, instead, the Michelins should have "won?"

What he said/implied was that the higher percentage number (lap,braking, acceleration) always denotes better performance. Where the anomaly lies is that you'd think a car (WS60) with better linear braking and acceleration would have an advantage on the ice course. But that didn't happen according to their testers. He first started to talk about subjective vs. objective, but I reminded him that all these tests were objective. I then presented my idea that the Contis have better dry handling (stiffer sidewalls, etc.), so maybe that had an impact on the ice course as well, and he agreed that was a possibility. That was it.

LMAO at Tirerack. Their practice of presenting the data as "percent versus reference" obfuscates the data. But as I read the ice test data, the Xi2 was the winner of all 3 ice tests. They assign the arbitrary score of 100 to the WS60 to make it appear the winner if you just glance at the numbers.

 

The Xi2 required 82.3% of the time the WS60 required, to accelerate to a fixed distance on ice.

 

The Xi2 required 84.9% of the distance the WS60 required, to stop from 10mph on ice.

 

The Xi2 required 96.4% of the time the WS60 required, to complete a lap on the ice handling course.

 

 

Didn't Consumer Reports also find that the Xi2 outperformed the WS60 on ice? (I'm not a CR subscriber, so I don't have a copy of their test report).

 

 

Saw this explanation later on the tirerack page:

"A score above 100% indicates performance better than the reference tire, while a score below 100% indicates performance below the reference."

 

So based on this, the Xi2 performed worse on ice than the WS60!

 

Tirerack gets a failing grade for data presentation!

Outahere,

I've got to disagree with your interpretation of TR's presentation. I don't believe that the percentages they present here http://www.tirerack.com/tires/tests/...y.jsp?ttid=122 denote raw numbers, but are a translation into their "percent vs. reference" standard of the raw data. For instance, the Xi2 did not need 82.3% of the time WS60 needed to accelerate to a fixed point; rather, the lower percentage assigned to Xi2 means that this tire was 17.7% slower in acceleration to that point. In all categories, lower % figures means that the particular tire performed less adequately than the standard pegged at 100% (or better, if over 100%). So I don't think you can fault them there. (That elementary misinterpretation of their own data would be pretty pathetic, were it true.)

^ Look at post #18 of his, which is a correction of misinterpretation from prior - that's what finally set me straight (in addition to what you'd stated of your conversation with their rep.) - allowing correlation between their (TireRack's) conclusions and the data.

I was so set in my ways that I couldn't break myself from the way that outahere interpreted things in the post you quoted above - which is the way that, logically, we as "car guys" have been groomed to receive time/distance data, that I couldn't read beyond the % values and realize what they'd actually represented.

I'll make an excuse and say that playing with some work data, at the time, got me more confused, but the truth is that I simply just wasn't getting a go on the "reading comprehension" portion, until you and outahere helped me reconcile.

With that, I'm glad that their data and conclusions are at least internally consistent - that they're reconciled with each other.

But it still doesn't explain the anomaly of why the Contis "lost" that particular comparo, which is an internal error/inconsistency/"anomaly."

Nor does it explain how their WS60/Xi2 data contradicts virtually that of all other recognized/reputable tests': and that while that would be a conclusion that I would have been willing to accept, had they defended it, per the quoted NASIOC reply by Luke, it seemed like they waffled on their data and conclusions, showing lack of confidence in either their data and/or methods, under the weight of open questioning and cross-citation of other published data.

What TR does is compute the % difference between the two times or two distances, then subtract that positive or negative number from 100 to get the "percent versus reference". It would be less ambiguous if they called this number a relative ranking, instead of calling it a "percent versus reference".

So in their scheme, the higher the "percent versus reference" number is, the better the tire performance.

 

It's a little clearer if you look at the data here:

http://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=125

I don't think it's a direct subtraction of positive or negative numbers (from the standard) representing the raw data from empirical measurement. I think all the raw data is "behind the scenes" and never appears here directly represented by percentage comparisons. The percent vs. reference is the indirect representation of how the cars stack up relative to one another's performance, one step removed from the raw data. So to say that the 82.3%, 84.9%, etc. directly reflects the proportional performance is incorrect.

To take the first category, ice braking: the 82.3% reference number says that the WS60 performed 17.7% better in this test than did the Xi2--by TR's definition. We don't know what the actual raw data was, nor can we infer (for instance) that the WS60 stopped at 100 feet and the Xi2 stopped in 82.3 feet.

But, as TS has said, this doesn't negate the remaining anomaly as to how the Conti did better on the ice handling course while the WS60 did MUCH better in braking and acceleration. The improved dry handling capacity of the Contis could explain some of that, but not all of it. But who knows?--if the ice handling course was all swoops and curves and straight acceleration and linear braking were minimized, then the handling prowess of the Conti could dominate the other two.

At this point I am still leaning towards the Conti EWC over the Xi2 and the WS60 (and my main concern is ice performance)--but I'm thinking that the WS70 could change that.

^ Of the Contis, I would urge you to wait-out until the more recognized overseas (as well as our brothers to the North) testing programs have sampled this tire, before making the leap. Given the conflicts within the TireRack's data on this particular test, I just don't know that you can trust *any* of it.

Unless, of course, you're up for the gamble.

Certainly, the WS70s may well change the picture - nevertheless, in the previews that various sources have been given, they are simply an incremental/evolutionary improvement over the WS60s, and slightly, albeit measurably and not insignificantly better than the Xi2...will that be enough of a margin to satisfy you?

And that's where my own dilemma currently rests:

As you may have seen from the other thread, I'm debating between the Nokian Hakka 7 and the Pirelli Winter Carving studded tires.

The Hakka 7s are agreed to be "the latest and greatest," topping virtually all tests.

I'm lusting for them.

But they're quite expensive.

The Pirellis trail close, in terms of performance, and are considerably more affordable.

stevehecht,

I happened upon something when reading in-detail the NAF 2009 testing, in researching my own planned studded-tire purchase this winter.....

The Conti Viking Contact 5 did not fare as well as the Xi2s, in the NAF comparison, in terms of ice - it was superior in the snow.

From various pictures of the Contact 5, it seems to be identical to the EWC, but honestly, I don't know, there may be more subtle differences.