Quote:
Originally Posted by Me&You
I'm certain that it's been said many times in this thread, but "winter" tires aren't just for the benefit of clawing through snow and ice. They're made of a different rubber compound than a summer or "all season" (aka - best at nothing) tire that stays softer in cooler temperatures. I said cooler, because most "summer" tires are about as hard as hockey pucks under 3°C, and while the roads may be clear and dry a lot, it sure as shit is cooler than 3° for a lot of the winter around here.
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And winter tires begin to suffer performance issues once the temps climb above +5 or so (as high as +10 depending on whose marketing spin you believe). ESPECIALLY with a light skim of water on the road surface. The braking distance lost at warm temperatures can actually exceed what you gain in the cold temps.
Which makes them suffer just as badly in a city where we see above-freezing temperatures throughout the winter (but especially during the shoulder seasons where we get -10 one day, +10 the next). December-January is really the only period they do much consistent good here, but because we normally get snow from October through May, people use them for far longer than is smart.
Also, frictional heating always seems to be ignored in tire discussions. Anything above -20 and your all season tires soften up pretty fast once you're on the road. A matter of minutes, usually. Much below that - you're driving on square tires no matter what. I've never seen a tire that performs well at -30 or colder, which is why people in truly cold climates often don't bother with them. I know the manufacturer claims of -40, but having lived in one of the coldest cities in the country I just don't buy it. Hockey pucks at -35 with any kind of tire.
I've tested my braking distance with all sorts of tires, and short of the first couple of minutes when it's -20 or so, on dry pavement it doesn't really change much. At least if you aren't tailgating, where that extra 10% might make a difference. The biggest difference winter/all-weather tires makes is in the icy slush we have as it warms up here. For those few days, they're a godsend (especially with accelerating/higher speed turns).
We really need someone to formulate a tire for Calgary's unique climate. Unfortunately all seasons cover off most conditions the best, and they're a compromise. Unless you're perfect at predicting the weather, or you can change your tires depending on the day. I actually know people who switch between their vehicles (each with different tires) depending on the road conditions, but that's obviously not practical for many people. The closest I've found are so-called "all weather" tires which are almost rated as good as winters in cold/snow, but are designed to work well in summer as well. They're really just fancy all seasons so you're making a tradeoff no matter what, but they do work pretty well here.