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Snow/Ice winter tires

784 messages,  Last post on Dec 17, 2011 at 12:41 PM

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Messages Page 78 of 79

#765 of 784 Perhaps a bit of history of "All Season" is in order! by capriracer

Sep 17, 2011 (4:34 am)

When radial tires first came into the US market, it was noticed that snow traction was much better than with bias tires. It didn't take long for someone to realize that a tire could be made more aggressive - and get improved snow traction - with only a slight loss of wear - the first all season tire. Others followed suit.
 
But this created a problem for the California Highway Patrol who regulated what vehicles were allowed to go into the mountains in winter. Their regulations required SNOW tires - amd while they understood that All Season tires had better snow traction than bias ply tires did, they needed something concrete to work against. So the Rubber Manufacturers Association (RMA) created a verbal description of what an all season tire looked like and Cailfornia wrote a regulation around that definition with the letters "M" and "S" as indicators. Put specifically - those two letters could only be used if, and only if, the tires met the definition - and the term "All Season could only be used if, and only if, the tire had an "M" and "S" on the sidewall. Other tires could have those letters - all terrain, winter tires - but the intent was to delineate street passenger car tires that had snow capability.
 
The letters "M" and "S" could be separated by a "+", or a "-", or a "/", or nothing at all, but when the letters appear, those mean "all season" and vice versa.
 
So you may ask: "Why didn't they mandate a test rather than a description of how they looked!" Because snow traction testing was in its infancy and there was lots of variability. In other words - it wasn't reliable enough.
 
Fast forward a couple of decades: The Canadians wanted to create a regulation for winter tires. They knew that some all season tires weren't vey good in the snow (although clearly superior to the old bias ply tires), but they wanted something that clearly delineated a superior winter traction tire. Again, the RMA stepped in and came up with a test and a symbol (Commonly called the "SnowFlake Symbol"). Needless to say, that snow traction test had become much more repeatable and reliable by then so the test had vaildity to the real world.
 
That is where things are at the moment.
 
But there is a problem: Many all terrain tires will pass this test - as will some agressive all season tires. That makes it difficult to enforce a "Winter Tire Only" regulation. So the Canadians have proposed a more agressive test and an approriate symbol to match - and they have run into technical difficulties. The Canadians would like to add ice traction to the testing protocol - BUT - tires that are really good in snow aren't necessarily really good on ice and vice versa. So they are have some difficulties writing a regulation to deal with this. They need to work out the bugs before a new symbol can be created.

#766 of 784 Re: Perhaps a bit of history of "All Season" is in order! [capriracer] by Mr_Shiftright HOST

Sep 17, 2011 (9:18 am)

Replying to: capriracer (Sep 17, 2011 4:34 am)
Interesting stuff....but really now, aside from studded tires, or chained tires, is any tire really "good" on ice? I mean, actual ice. Seems unlikely to claim such.

#767 of 784 Re: Perhaps a bit of history of "All Season" is in order! [Mr_Shiftright] by shipo

Sep 17, 2011 (10:08 am)

Replying to: Mr_Shiftright (Sep 17, 2011 9:18 am)
The Michelin X-Ice tires which I ran on my 530i were surprisingly decent on ice.

#768 of 784 Re: Perhaps a bit of history of "All Season" is in order! [shipo] by Mr_Shiftright HOST

Sep 17, 2011 (12:25 pm)

Replying to: shipo (Sep 17, 2011 10:08 am)
yeah but not "ice" ice. You mean melted-snow type ice, right? You've seen videos of cars and trucks sliding backwards down hills? That's what I was talking about.

#769 of 784 They do ice now! by guitarzan

Sep 17, 2011 (1:04 pm)

I am not qualified to respond about pure ice. I can however state that it is actually difficult to get the anti-lock brakes to kick in, with Blizzaks on the car, in the winter here in Cleveland. We're talking a light, late model Celica with four large brakes. Snowy, slushy, icy conditions, it doesn't matter. If that top layer of microcells has not worn off yet, the car stops unbelievably well.

#770 of 784 Re: Perhaps a bit of history of "All Season" is in order! [Mr_Shiftright] by shipo

Sep 17, 2011 (1:47 pm)

Replying to: Mr_Shiftright (Sep 17, 2011 12:25 pm)
No, I'm talking about ICE, you know, the cold hard stuff that glazes everything it comes in contact with.

#771 of 784 Re: Perhaps a bit of history of "All Season" is in order! [shipo] by Mr_Shiftright HOST

Sep 17, 2011 (3:17 pm)

Replying to: shipo (Sep 17, 2011 1:47 pm)
I think we're talking about different things then. I was talking about sheer ice, or "black ice" as it is sometimes called. Even chains, studs or tank treads don't help very much on this stuff.

#772 of 784 Re: Perhaps a bit of history of "All Season" is in order! [Mr_Shiftright] by capriracer

Sep 18, 2011 (5:42 am)

Replying to: Mr_Shiftright (Sep 17, 2011 9:18 am)
Obviously, "good" is a relative term.
 
When the Canadians proposed the new regulation, they assumed that a tire that would have - relatively - excellent ice traction, would also have - relatively - excellent snow traction. It would have been nice if that was true, but, alas, that is not the case.
 
Clearly ice traction is going to be low compared to dry traction - but that wasn't the issue. It had to do with rating tires - and the assumption was that the average motorist would assume a highly rated winter tire would be highly rated for both snow and ice traction - and because they are not, there's a dilemma.

#773 of 784 Re: Perhaps a bit of history of "All Season" is in order! [Mr_Shiftright] by shipo

Sep 18, 2011 (6:50 am)

Replying to: Mr_Shiftright (Sep 17, 2011 3:17 pm)
You'd be surprised the difference in traction on "black ice" between say all-season tires and winter tires. The winter rubber compounds do in fact manage to find some grip where other tires do not; this is of course all relative.

#774 of 784 Re: Perhaps a bit of history of "All Season" is in order! [shipo] by Mr_Shiftright HOST

Sep 18, 2011 (8:35 am)

Replying to: shipo (Sep 18, 2011 6:50 am)
I was watching a video from TIRERACK on this subject since you brought up this interesting point. I think we were really on the same page but I was thinking of high speed traction on ice which of course is pretty impossible to ask of any tire.
 
But the TIRERACK video definitely shows that at slow speeds (10 mph) some tires perform quite well on ice (they used an ice rink). So I could see why picking the right tire makes a difference under those conditions.

Messages Page 78 of 79

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