Snow/ Winter Tires vs All Season
 

The Quebec Minister of Transport asked the Quebec Industrial Research Center (CRIQ) to conduct a series of tests in order to evaluate scientifically the performance of all-weather tires on compact cars, trucks and sport-utility vehicles. The test results conveyed simple and direct findings. The report concludes: "The tests carried out by the CRIQ are conclusive. They demonstrate that in general, winter tires perform better than all-weather tires. Based on experiments conducted one must conclude that winter tires provide better braking performance than all-weather tires, a central feature of road safety." ...........these tests have clearly demonstrated that braking distances were improved from between 16.6% to 25.1% on hard-packed snow with the use of snow tires. Acceleration tests indicated that acceleration times from 0 - 35 mph were reduced by about 11.1% for a four-wheel-drive vehicle and 40.1% for a small van. Although results vary from one vehicle to another and from one tire brand to another, the tests are conclusive. ........The foregoing is an excerpt from a book by Jacques Duval entitled The Auto Guide 2002.

But do you think people will listen to the report? hmmmmm
When you live somewhere with very well defined snow/no-snow seasons like Ontario, it should be a no-brainer to have dedicated Summer and Winter tires.
I used the stock Dunlop 5000's last winter and cold pavement was ok, but as soon as you hit snow, it was not a fun experience.

That test is fine if all you do is drive on ice, but studded tires suck on any surface that isn't ice. R&T had a test that showed studded tires on wet or dry (non-ice-covered) pavement increased braking distances and acceleration, and decreased cornering dramatically.

Makes you wonder why states like Oregon and Washington still allow them. Sure makes driving there no fun.