While out and about in yesterday’s 8″ “dusting”, I saw a large number of cars skidding, sliding and just plain going nowhere, even on plowed roads. That’s almost certainly because the cars were equipped with summer or “all-season” tires, in defiance of the certain knowledge that “all-season” refers to seasons in parts of the country that never see snow. If you live where it does snow, you need a different tire.
Edmunds did an interesting experiment testing the capabilities of “summer”, “all-season” and “snow” tires, first on snow, then on dry pavement. The result? Snows were pretty useless in dry California conditions, and fabulous in Minnesota, while summer tires were the reverse. All-Season tires gave the most balanced performance: they sucked in both conditions.
What can we make of all this? For one, low-friction surfaces demand respect. Our stopping distances in the wet range 30-40 percent longer than those recorded on dry pavement. Meanwhile, stops on snow consume at least three times the distance as they do on dry asphalt, even with the use of best-case tires in each situation.
Second, no single tire type excels on all surfaces, and the differences between each are sometimes striking. These differences are so massive, in fact, that we feel that certain generalizations can be extrapolated from our small trio of carefully selected test tires.
To the surprise of exactly no one, our winter tires dominate in snow and the summer tires dominate in the dry. The eye-opener here relates to wet performance, where a well-developed summer tire embarrasses an all-season tire made for the same car by the same folks. Anyone who never sees or visits snow would be very well served by summer tires for year-round use.
Another key take-away from this exercise is the utter worthlessness of those same summer tires on snow. Anyone who uses snow tires in winter and summer tires the rest of the year — a good strategy to maximize performance and control all year — needs to time the switch-over carefully to avoid getting caught out by the first rogue snow accumulation of the season.
And the lameness of summer tires on snow makes it easy to see why the California Highway Patrol and other local authorities can have a hair-trigger when it comes to requiring snow chains. It also explains why so many carmakers spend a lot of energy on all-season tires; they don’t know where you live or where you’ll drive, so they want to make sure you’ve got passable winter rubber.
But in delivering this capability, all-season tires sacrifice a noticeable bit of dry and wet performance. Meanwhile, snow and summer tires provide clear benefits to those who can use them. In this particular test, at least, all-season tires live up to the old figure of speech our old dad used to trot out on occasion: “jack of all trades, master of none.”