Winter-fest: Brrr! The colder it gets, the warmer a winter tire stays

March 1, 2007

It is a bit of a misnomer to say that the terms "snow" and "winter' are interchangeable when it comes to tires. The former really has evolved into the latter.

In general, true snow tires used to be fitted on vehicles for use in heavy snowfall. They were designed for a condition.

What we call winter tires today work well under snowy conditions; however, they are designed for temperature, so they also perform well on dry, wet and icy road surfaces during the winter season. They also, in some cases, provide a quiet, comfortable ride as well!

At the recent introduction of the General Altimax Arctic in Big Sky,

Mont., Continental AG's Dr. Burkhard Wies, head of global tire line development, said you would get slapped on the wrist by company executives for even using the phrase snow tire.

According to the Rubber Manufacturers Association, close to eight million tires, or 4.1% of the replacement P-metric tires it estimates were shipped in the U.S. in 2006, had traction and snow tread designs. Winter, all-terrain and traction treads are included in the total.

Continental says between four and five million of those units were true winter tires, complete with the RMA's mountain snowflake designation. Another six to seven million winter tires were sold in Canada in 2006.

The importance of winter tires when the weather dips below 45 degrees Fahrenheit cannot be understated, even when the vehicle is equipped with traction controls (see chart). "There seems to be a misconception that four-wheel drive systems provide extra traction and handling when driving in winter weather," says Melissa Montisano, general marketing manager for light truck tires at Goodyear Tire & Rubber Co.

Goodyear's new Goodyear Ultra Grip SUV and Ultra Grip Performance tires will be ready for the 2007-2008 winter season -- as will the General Altimax Arctic, Nokian Hakkapeliitta 5 and Sport Utility 5, and Blizzak WS60.



By Bob Ulrich

Sometimes it does take a rocket scientist to design a tire. Dr. Burkhard Wies, vice president of tire line development worldwide for Continental AG, helped develop the new General Altimax Arctic. His credentials include an undergraduate degree in physics and a PhD in mechanical engineering; his thesis relied heavily on combustion research.

Wies knows everything about the tire, which is made with a higher percentage of natural rubber than many of its competitors, thanks to extensive testing. Some of the following tests were performed by an independent third party, so he is confident that the tire performs as advertised.

1. Load. The Altimax Arctic was tested on different vehicles. "We get a representative sketch of the market, so we don't test on just one car." Wies says some of the vehicles were overloaded.

2. Temperature. For example under snowy conditions, at 32 degrees Fahrenheit or less, the compound had to be supple enough to bend the block to open the sipe to grip the road or ice. He says braking performance is targeted.

3. Winter conditions. Was the snow packed or loose? Was the ice wet or dry? Wies says all this was tested.

4. Wear. Wies admits that the wear testing on the Altimax Arctic was done more by association, per research done by its Gislaved subsidiary. "We have done studies on wear -- not for this tire -- on tires with similar pattern used in Sweden."

5. Irregular wear. Continental field tested the tires with and without studs with the help of its fleet customers. "The stud has to work and wear at the same time."


6. Front-wheel and rear-wheel drive. The tire was tested on both types of vehicles. Wies says a 4x4 test on ice, "especially under heavy load conditions," was a first for the company.

7. Pressure. "Yes, we reduced pressure slightly -- not significantly, maybe 20%. Grip normally increases as the pressure decreases. It can, of course, destroy mileage."

Wies says Continental does a lot of subjective testing as well, such as putting two winter tires on the front of the vehicle even if you wouldn't normally do that "so as to test braking, not steering."

The tires also were tested on vehicles with traction control, ESP (electronic stability program) and ABS (anti-lock brakes). In Europe, traction control is sometimes referred to as ASR (anti-slip regulation). "It's easy to make a tire good in a high-slip area, but you need it to perform in a low-slip area, too," says Wies.

General Altimax Arctic: It will be available in 26 sizes next winter

Continental Tire North America Inc. is touting the Altimax Arctic as the first true winter tire marketed under the General brand name. It combines unique grooves and sipes with an all-weather, dual tread compound for high performance at low temperatures.

The company expects to have 26 studdable, Q-rated sizes of the Altimax Arctic ready for shipping in the third quarter. The size breakdown is as follows:

* 13 inches: 175/70R13.

* 14 inches: 175/65R14, 185/65R14, 185/70R14.

* 15 inches: 195/55R15, 185/60R15, 195/60R15, 205/60R15, 185/65R15, 195/65R15, 205/65R15, 205/70R15, 215/70R15.

* 16 inches: 205/55R16, 215/55R16, 225/55R16, 205/60R16, 215/60R16, 225/60R16, 235/60R16, 215/65R16, 225/70R16.

* 17 inches: 225/45R17, 235/45R17, 205/50R17, 235/65R17.

According to Continental, the 26 sizes will cover 68% of the domestic market and 72% of the Canadian market based on industry volume.

The tire features Reactive Contour Technology, which allows the contour of the tire to react to different road conditions for optimum road contact throughout the life of the tire.

"Our target in the winter tire market is to grow up to one million tires in the next two to three years," says Andreas Gerstenberger, executive vice president of sales and marketing for Continental Tire North America's replacement passenger and light truck tire business unit.



By Mike Manges

"We have a policy that 25% of our sales has to come from new products," Nokian Tyres plc spokesman Kari-Pekka Laaksonen told a group of North American dealers at a press conference in Ivalo, Finland, last month.

"We are totally renewing our summer and winter tire line-ups."

At the forefront of that revitalization are two new winter tires: the Hakkapeliitta 5, a passenger tire designed for severe winter weather, and its light truck counterpart, the Hakkapeliitta Sport Utility 5.

Dealers got a firsthand look at the Hakkapeliittas during a day-long ride-and-drive event at Nokian's snow and ice-covered test track near Ivalo, more than 150 miles into the Arctic Circle.

The Hakkapeliitta 5 contains more studs than its predecessor, the Hakkapeliitta 4, and uses Nokian's newly designed square studs that apply more force to road surfaces during braking.

Also integral to the tire's gripping power are "wings" in its outer shoulder area made of a proprietary compound that protects against tread cracking.

Nokian officials say the Hakkapeliitta 5 performs better than the Hakka 4 in several critical areas, including ice handling and braking, slush planing and dry surface handling.

It is available through Nokian's La Vergne, Tenn.-based subsidiary, Nokian Tyres Inc., in 41 sizes, ranging from 13 inches to 19 inches.


The Hakkapeliitta Sport Utility 5 also is available in North America in 31 sizes, ranging from 15 inches to 22 inches in diameter.

Similar in design to its passenger counterpart, the tire contains stabilization elements between shoulder blocks to make them stiffer. It boasts an aggressive rim guard and also uses Nokian's square studs.

Slush funding

Nokian unveiled an all-weather tire in Ivalo, the WR G2, that can be used year-round.

The tire exhibits "outstanding slush and aquaplaning properties," according to Nokian officials.

"We've cut the shoulder to a certain angle so when you drive, it cuts through the slush. Slush is one of the most dangerous and most common elements on winter surfaces."

Among other features, the WR G2 sports a "full-silica" tread compound that contains canola oil for extra winter surface grip.

Molded onto its sidewall is an "info field," also found on the Hakkapeliitta 5, that tells techs where to place valves and also the correct inflation levels. The WR G2 will be available in the U.S. and Canada this August.

Great expectations

Nokian officials also discussed North America's role in the company's growth during the Ivalo event.

Nokian's North American sales increased by 18.3% last year. (The U.S. and Canada represent 9% of Nokian's total sales, with some 1.3 million units sold there during 2006. By contrast, last year Nokian sold 3.4 million tires in Russia, the Ukraine and adjacent countries, the company's highest-growth sales region.)


"We're really focused on growth," Laaksonen told North American dealers, many of whom have experienced a downtick in winter tire sales due to unusually warm weather.

Al Harmon, owner of Harmon's Tire in Ellsworth, Maine, says his winter tire sales are down 25%.

He plans to promote Nokian's new winter tires at his shop. "An all-season tire is a compromise."

Jason Lowing, sales representative for Schneider Tire, a retail/wholesale operation in Marne, Mich., says his winter tire sales were down 15% last year versus 2005.

"This winter has been horrible. We're sitting on all kinds of snow tires." Lowing says he's looking forward to selling the WR G2. (Tire studs are outlawed in Michigan.) Its snow handling capabilities will be "a big selling point."


Bridgestone Firestone North American Tire LLC chose to stage the recent introduction of its new Blizzak winter tire in, appropriately, the wintry wonderland of Steamboat Springs, Colo.

The new Blizzak WS60 with Uni-T utilizes NanoPro-Tech, a Bridgestone proprietary technology used in tread compounding and formulation.

The WS60 tread is composed of two different compounds. The outer 55% is a Tube Multicell compound comprised of thousands of microscopic cells or pores which resemble Swiss cheese at a microscopic level. As these pores are worn away, new pores are exposed, creating thousands of biting edges that grip the road and wick water away from the tire’s contact patch to improve grip. The compound also features particles that bite into ice for better traction, similar to studs.


The remaining 45% of tread depth is a high silica winter compound which provides solid tread block support to the softer Tube Multicell compound.

The WS60 also has a tread depth indicator that indicates when only 10% of the Tube Multicell compound is left.

WS60 in, WS50 out

Bridgestone estimates there have been more than 100 million Blizzaks sold worldwide since the line was introduced in Japan in 1988. (The line was introduced into Canada in 1992 and the U.S. in 1993.)

The Blizzak WS60 will replace the Blizzak WS50 tire when it becomes available in the fall of 2007. Here’s why.

* The WS60 has less tread void ratio compared to the WS50, but the ratio is more efficiently used, according to Bridgestone.

* The WS60 uses crisscross sipes and zigzag sipes with a three-dimensional design to lessens tread squirm, giving more sipe edge density than the WS50. This gives the WS60 greater traction.

* The WS60 has a unidirectional tread pattern with wide shoulder blocks and a wide, straight center groove that give the tire performance characteristics that meet or, in most cases, surpass those of the Blizzak WS50.

* The WS60’s Tube Multicell compound features 60% larger cells or tubes than the WS50. These cells increase the tire’s resistance to hydroplaning and improve driving and braking on snow- and ice-covered roads.


The new Blizzak will be available in 38 R-rated, 70- to 45-series sizes ranging from 14 through 17 inches. In addition to the WS50, the WS60 also will replace the Blizzak Revo 1 series.

All-season vs. winter

What is the difference between a snow tire and a winter tire? William “Bill” VandeWater, consumer products manager, sales engineering, says the terms sometimes are used interchangeably. “Snow tires are a sub-category of winter tires. ‘Snow’ is a condition, and ‘winter’ is a season that has conditions within it.”

BFS designs all its winter tires to perform well on snow, ice, cold road surfaces and wet/slushy surfaces. Of the four, snow and ice require different solutions, says VandeWater. Snow’s physical properties and high-speed capability also influence design solutions as well.

Some regions that have a lot of ice, like the Mid-Atlantic areas of the U.S. and Japan, require a different tire than in colder areas with “drier” snow like northern Canada and Scandinavia.

Bridgestone Firestone has two lines of winter tires; both meet the company’s four major design standards. However, the Blizzak Tube Multicell line is weighted toward superior severe snow and ice conditions, while the Blizzak Lemellen line is weighted toward high-speed driving on cold wet and snow-covered roads.

In comparing tires for winter driving, VandeWater says that in the U.S., the really important difference is between all-season tires, marked M+S, and winter tires, which bear the snowflake symbol on the sidewall. The M+S marking is more of a cosmetic standard – i.e., “The tire can look like a snow tire, but it doesn’t have to perform like a snow tire. From a performance viewpoint, M&S tires will not necessarily perform well in certain kinds of snow.” Winter tires, however, must meet quantifiable performance standards.