Higher revenue from fines!

Q. what is the average temp in GTA say between Nov. and March.

If its below 7c (and i have know idea what the temps is) then that would warrent mandatory winter tires for that period for example

Nonsense, You cant mandate something based on wishy washy statements by manufacturers representative


HAVE YOU SEEN DRY BRAKING DISTANCE VS TEMP DATA???

No? Me neither.


According to some (who?) performance STARTS to degrade at 7C


HOW MUCH DOES IT FALL OFF, HOW WAS IT TESTED, WHO IS TELLING YOU THIS, WHAT IS THEIR MOTIVATION.

Having an annual safety test on vehicles would have a lot more impact on breaking performance here. As dbd points out, the only way to make driving risk free is to use the train.

A static test of friction is utterly pointless...as a tyre rolls it builds up heat, so what temperature is the rubber of an all season actually at after 5 minutes at 60kmh in -5 ambient temperature, and how does that level of grip compare to a winter tire doing the same thing. That's the sort of hard data that would be useful to make an INFORMED decision.

Why?

Tell us by how much the braking distance is affected on a dry road at 7C, 6C, 5C etc. and perhaps more people might be willing to listen.

This article was quoted earlier in the thread and although it has some good points it loses credibility when the author claims that at -5C an all season tire has about as much grip on a road surface as a hockey puck on ice.

A totally ridiculous statement.

http://autos.canada.com/components/p...3-8366cc87deae

just spent almost an hour trying to find the Swiss version of top gear with Marc Surer as he did anualy a winter tire test, i failed looks like the programm doesnt run any longer so i cant offer the proof you all want so badly.. Oh and its just started to snow:curse:

Is he testing in the dry and comparing performance to all seasons? All the testing I've found is;

A: Largely anecdotal
or
B: Focused on the improved grip in ice and snow, rather than performance on dry roads
or
C: Focused on comparing different brands of winter tires

The problem with that is the reality in S Ontario is mostly the roads are clear of ice and snow, and anecdotal evidence doesnt allow for objective decision making. Ontarios climate is marginal for snow, compared to the provinces to the east, and marginal for temperature compared to the provinces to the west, so its not necessarily the no brainer it might appear to be.

What I'd be really interested in seeing is a comparison of stopping distances between all seasons and winter tires on dry roads at various temperatures.

Im now serching the ADAC websites hold on or help look

Chew on this http://www.adac.de/Tests/Reifentests...rcePageID=8762

My german isnt the best, but as far as I can see there is no discussion of performance at different temperature on the test methodology page?

tests were done on Dry, rain soaked, Snow, and on an ice rink...
it does not mention at what temps the dry were done at, but I assume cold as these are winter tests... bloody nora what more do you want Iain , Blood,

According to the APA (Automobile Protection Association)

http://www.apa.ca/template.asp?DocID=49

Seems to back up Iain's argument quite well don't you think.

Still can't find any stats yet.

Let me spell it out in short words


I want to know how cold it needs to be before all seasons become seriously compromised compared to winter tires when driving in normal (ie dry) road conditions.

If all seasons make a ten foot stopping difference at 80km when its -10, but only a two foot difference at zero , then I see no point in making everyone change. If it makes a 50ft difference, then there is an argument to be made for a legal requirement...that's where I am coming from.

With that sort of data its possible to do some sort of fact based risk assessment based on average temperatures and the like in this area.


I dont doubt for a second that winter tires perform better in the extreme cold and in snow and ice. I am no so convinced when it comes to days like today and the rest of the five below zero days of winter that the performance difference is terribly great. They should frame the legislation with average days (like today) in mind, and trust drivers to adjust their behaviour when the conditions are sub par.

I suppose it could even be argued that the chunky tread block design and softer sidewalls might even be compromising handling and accident avoidance more than the advantage in flat out stopping power is worth. But for the sake of the miles I drive in the cold, and the snow and ice we get out here in the country, Ill keep my winter tires. If I lived in Toronto, I might not be as convinced of the benefit on average, so I say it should be up to the person to decide, not the government. Of course I get 5% of my insurance for having winter tires too...

If you're interested in techincal data, this might be of use:

This paper presents an effectively unbiased nonlinear estimation scheme which identifies tire longitudinal stiffness and effective radius using GPS and ABS wheelspeed sensors. This estimation strategy is then used to experimentally identify the longitudinal stiffness and effective radius of a summer tire and a winter tire under several different test conditions. The data clearly shows that there are several important parameters which govern tire longitudinal stiffness behavior in the low slip region. At a minimum, inflation pressure, tread depth, normal loading and temperature have a strong influence on longitudinal stiffness estimates; the change from dry to wet asphalt had the smallest effect on longitudinal stiffness estimates.

http://ieeexplore.ieee.org/stamp/sta...isnumber=27842

Lots more info out there - Google Scholar gives the best search results:

Abstract:
The paper presents original research and summarizes the published literature regarding tests of tire-road friction in winter conditions. The original research investigated the effect of temperature variation on tire-road friction on a variety of winter driving surfaces, including an investigation of the variation of friction coefficient with the dispersion rate of applied sand. Tests were conducted on surfaces including bare asphalt, black ice, ice and snow, ice and snow with a variety of sand overlays, ice and snow with a layer of fresh snow, and glare ice at temperatures ranging from -42\mDC to -4\mDC (-44\mDF to 25 \mDF). The published literature relating to tests of friction in winter driving conditions was surveyed, and data from the original research and the previous publications are presented in a uniform fashion.

http://www.sae.org/technical/papers/960657

Not bad for a pea brain.


Now, whos going to stump up the $15 to see what it says although I dont think it necessarily gives info on tire performance per se.. just the coefficient of friction of various road conditions.

I suspect he was buying the winter tires locally, I looked into moving to Switzerland recently, and the regulations about the vehicles was frightening, many components had to meet the Swiss standard and even if they were available same model almost across the border in France, would still invalidate you insurance
They have a very tight policy on what can and cannot be used on each car, right down to the size of rims that are allowed with which tire
And its policed and enforced with high fine and often resulting in issues with your insurance cover until its fixed to the Swiss standard