By Steve LaFerre
Senior Editor
TIRE REVIEW Magazine

Thirty years ago, everyone could describe a snow tire – big, knobby, luggy tires with lots of void areas. They weren’t sophisticated, they used the same compounds as regular passenger tires and they were OK for the market at that time. But, they were noisy and wore out quickly in the heat of summer if you left them on all year.

Then, Goodyear changed everything with the introduction of the "all-season" Tiempo in the late 1970s. An instant success, this tire was billed as a year-round performer that eliminated the need to make the annual trek to the dealership to change over to snow tires. Virtually every U.S. motorist – and automaker – accepted the all-season concept.

Technology took another leap in 1993 when Bridgestone introduced the Blizzak. It wasn’t the world’s first dedicated "winter" tire, but it was the first to be heavily marketed on these shores.

Although early versions of the winter tire suffered from premature wear, that problem is ancient history, as tiremakers developed better compounds and more effective tread patterns. Today, more drivers are switching to dedicated winter tires for winter driving.

Of course, the story here is growth. We know, for example, that from November 2004 to November 2005, dedicated winter tire shipments were up; winter tires shipped into heavy snow areas during this period stand at eight percent of the tire market, up from a year earlier – two percent. That’s a 300 percent growth rate, or roughly 4.5 million tires.

At the same time, sales of dedicated "summer tires" are growing at an equally astonishing rate.

But, are we really seeing a growing need for dedicated seasonal tires? Depends. Although some 95 percent of all tires shipped in the U.S. today are still termed "all season," that may have much more to do with an evolution in tread designs and compounding than a reluctance by consumers to return to the two-sets-of-tires days. Many of today’s "summer tires" retain all-season status, for example.

WHAT’S REALLY UP?
Have you noticed we don’t call a snow tire a snow tire anymore? We call them "winter tires" because of the technology rolled into the tread area as well as extraordinary compounding. While all-season tires work well in the winter in most of the U.S., winter tires are recommended for the areas where winters are fierce and snowfall is significant. One tire man put it this way: “You need winter tires where the roads are white and not black.”

Compare U.S. tire shipment numbers with Canada’s. Some 30 percent of all tires shipped in Canada are dedicated winter tires. That figure drops considerably when you look south, even in significant winter belt areas like New England, portions of the northern Rocky Mountain region, areas around the Great Lakes, plus the Dakotas and Minnesota. When the ambient temperature drops to 10ºF and below, specially compounded winter tires get down to business. At these temperatures, all-season tires become more like plastic – exactly what you don’t want in a winter tire. A dedicated winter tire operating in extreme weather conditions affords a 20 percent to 25 percent braking advantage, along with easier starting, experts say.

With that in mind, it’s no real surprise that Goodyear has again upped the ante with its all-season Assurance. In every U.S. state where snow is not a major factor, Goodyear’s Assurance with its "triple-tread" design and compounding works just fine, says the company. In fact, Goodyear said its new tire can handle modest amounts of snow nicely – and it comes with an 80,000-mile limited treadwear warranty. Sales numbers bear out that the Akron tiremaker is on to something.

“There are only two ways to manufacture dedicated winter tires,” the company said. “You make soft compounds and add lots of biting edges, both of which aren’t good for summer tire life.”

While Goodyear admits (for now) that its Assurance is no match for pure-bred winter tires, a close examination of newer so-called "all-season" tires from many tiremakers shows that some of today’s models look more like traditional winter tires, with sharper tread element edges, increased siping and even hybrid tread compounds. Others have characteristics we’d normally attach to performance-level tires, with sweeping grooves, greater tread-to-void ratios and wide circumferential grooves.

Technology appears to have closed the gap between the types, but will we ever see one ultra tire that delivers high levels of traction, braking, handling and wear in every weather condition, every part of the country, every month of the year? No, not while tiremakers continue to see growth opportunities in dedicated winter products.

MINUS SIZING
“We see the all-season tire as a compromise when used in significantly deep snow at significantly low temperatures,” said Michelin, which offers a wide range of dedicated winter and summer tires and all-season units. Its X-Ice and Pilot Alpin PA2 for cars and the Latitude X-Ice for light trucks/SUVs tells us that the tiremaker sees a strong need for winter products.

According to Michelin, winter tires have evolved into highly engineered products that address a range of driving conditions. Not only are they the optimum choice for drivers in heavy snowfall areas, they are also suitable for drivers in moderate snowfall areas with icy conditions. The compounds in these tires use molecular or chemical adhesion to cling to the road surface. Coupled with a tread design that provides more lateral grip or side-to-side traction, winter tires make a difference.

Michelin also called attention to minus sizing for winter tires. “When you cut a pizza, you use a thin little wheel to cut through the crust, cheese and condiments. It’s the same with a winter tire. Narrower is better than wider. Wider tires tend to plow rather than slice. We are now seeing retailers recommending moving from a 60-series winter tire to a 70-series tire that digs in to penetrate snow.”

This is simply plus sizing used backwards. A 2003 VW Jetta GLX VR6, for example, would have its OE 205/55R16 (or optional 225/45HR17) stored for the winter in favor of minus-one or minus-two size 195/65R15 tires on 15-inch wheels. With thinner tires, snow traction is improved, Michelin says.

So, has practicality and safety (dedicated winter tires) won out over convenience (all season)? “It is believed that shipments of dedicated winter tires might already stand at 20 percent of all tires shipped into the U.S. winter belt,” said Michelin.

Compared to the Canadian market, does that mean a 10 percent growth opportunity for such a tire in this country? “We think so,” said Michelin. In fact, dedicated winter tire shipments in Canada, already at 30 percent, are predicted to climb. As that happens, the U.S. winter belt market will probably follow.