WINTER PERFORMANCE TIRES: Unless you travel by dogsled or reindeer and sleigh, you need to read this
In the automotive realm, the true meaning of the word "performance" is not limited to wide-open-throttle operation or striving to achieve the highest possible straight-line or cornering speed.
Performance, in the true sense, refers to optimizing a vehicle's capabilities in order to improve or enhance a vehicle's ability to perform specific tasks, regardless of the speed involved. The "fast-factor" is simply a by-product of any performance improvements.
When we consider "performance" tires, what we're really after is a tire that will optimize the vehicle's capabilities for a specific set of criteria. No single tire model is able to provide maximum performance under all circumstances. Tire designs and materials can be formulated to provide maximum tread life, maximum dry traction, maximum wet traction, maximum ride comfort or maximum traction in snow and ice.
Of course, compromises are routinely made in order to enhance a number of performance properties in a single tire model in order to provide higher-than-normal performance in both wet and dry conditions, or with "all-season" tires to provide traction in both warm/dry, warm/wet, cold/dry, cold/wet and snow/ice conditions. However, if you expect to drive the vehicle in snow and ice conditions and demand the best possible performance, the only solution is to select winter tires that have been specifically designed for winter conditions.
Installing dedicated winter tires provides two distinct benefits: You gain maximum traction and performance in winter weather, and you prolong the life of your summer tires by storing them for a few months each year. If you opt to install the winter tires on a set of steel or less expensive alloy wheels, you also save your customer’s expensive summer alloys from the harsh effects of slush and road salt.
Winter tire properties
Why are "winter tires" better for cold and snow/ice driving? A number of factors are involved, not the least of which are tread compounds and tread designs. An ultra-high performance summer tire's compound is designed for operating at higher temperatures.
This compound's makeup will likely tend to become "harder" (the rubber will tend to become more like plastic) when exposed to temperatures below 32 degrees F, which detracts from tractional properties. Winter tires utilize special compounds that remain pliable in cold temperatures. In addition, compared to non-winter tires, their tread patterns tend to feature more thin sipe cuts, which act as a series of small "squeegees" that improve the tire's traction in slush, snow and ice.
This explanation is extremely basic, but you get the point: Winter tires primarily are designed to provide the best possible grip in winter weather conditions. If you want to experience the best tire performance during cold winter months, you need dedicated winter tires. This applies to any vehicle that you intend to operate during winter, whether it's a 150-horsepower compact car or minivan, or a 600-HP ultra-high performance car.
Winter tire drive and learn
Winter tires, due to their generally deeper tread depths and tread/compound features, likely will provide more tread squirm than performance summer tires. To become more familiar with the differences, you should take the time to become familiar with the new handling characteristics of the winter tires you are selling. Then you can pass along the knowledge to your customers -- or make the sale because of it.
Since winter tires feature softer compounds and lower speed ratings (commonly a Q rating, which indicates a maximum speed of 99 mph), handling response will be lower compared to summer high performance tires. This won't create a problem as long as you exercise care as you become accustomed to the difference in handling.
In order to gain maximum benefit from the winter tires, you'll need to log a few miles to "break the tires in" as any remaining tire mold lubricant wears off of the tread surfaces.
In addition to becoming accustomed to the slightly different handling attributes of a winter tire, you need to be aware of a few maintenance issues as well. While proper wheel alignment settings are obviously important in any application, because winter tires generally feature more aggressive tread patterns and softer compounds, they may be more sensitive to tread wear induced by incorrect toe-in and camber angles. In other words, any tire will wear unevenly if alignment angles are incorrect, but winter tires will wear even faster if alignment is off-specification.
Tire inflation, as we all know, will affect tread wear. If under-inflated, a tread will wear faster at the outer tread areas. If over-inflated, wear will be concentrated at the center of the tread area. While the use of winter tires does not affect the inflation issue, you should be aware that any tire's inflation pressure will be adversely affected by cold weather.
Air expands when heated and contracts when cooled. In winter weather, inflation should be checked frequently to avoid under-inflation. For every 10-degree Fahrenheit change in air temperature, a tire's internal pressure will change by about 1 psi. (Inflation pressure will rise in hot weather and drop in cold weather.)
If you adjusted cold tire pressure in September during a 75-degree F day at, let's say, 32 psi, when the temperature drops to 25 degrees F in December (a drop of 50 degrees), tire pressure may have dropped to a mere 27 psi, which would certainly accelerate tread wear.
The point we're trying make is that your customers should be told to check tire pressures more often during winter weather. It may not be convenient, but it's necessary.
Also, be sure to keep caps on all valves. Unprotected valves can quickly become contaminated and seize-up, making it difficult or impossible to read or adjust pressure. And any moisture that enters and freezes in the valve can cause tire pressure to escape. Valve caps are not decorative items. They are vital to the operation of the valves.
Winter tires and ABS
Many people may be lulled into a false sense of security during the winter months because their vehicles feature anti-lock braking or all-wheel-drive. An anti-lock breaking system (ABS) does not negate the need for dedicated winter tires if the highest level of performance is desired.
ABS minimizes brake lockup, but does nothing for tire traction. Traction control systems are designed to prevent tire spin, but again, this does not improve tire traction. Certainly, FWD or AWD places engine weight load over a drive axle, which improves snow/ice traction. But in order to gain maximum steering control, braking, acceleration and handling traction, winter tires are the answer.
By installing performance winter tires, you multiply the benefits of a FWD or AWD system. Even if the vehicle is equipped with full-time four-wheel drive (which may help in terms of acceleration), braking and steering control may still be lacking without the benefit of winter tires.
Two winter tires vs. four
OK, so youvee sold your customer on the benefits of winter tires. Since his vehicle features one drive axle (FWD or RWD), he only needs to buy two winter tires for that drive axle, right? Wrong! Operating any vehicle with a mixture of different materials and construction is never a good idea. The difference in handling properties can lead to understeer or oversteer and poor handling feel.
In addition, using different tire models on the front and rear axles also can confuse the vehicle's ABS or traction control system, since road traction will differ from front to rear.
Whenever you make any tire change, regardless of the season, always install a matched model set. Otherwise, you're just asking for problems.
Winter tire symbol
Identifying purpose-built winter tires is easy, thanks to a National Highway Traffic Safety Administration (NHTSA) mandate that requires a unique "mountain/snowflake" symbol on the sidewall.
While the standard "M+S" (mud and snow) symbol simply indicated that the tire tread featured cross slots and cross pockets, this was not a performance criterion. The new "mountain/snowflake" symbol indicates that the tire has met specific performance criteria for snow and ice traction. If you see the mountain/snowflake symbol, you know that the tire meets specific winter performance criteria.
You should be aware that not all dedicated winter tires may feature this symbol, since tire molds which don't feature the symbol may still be in use to produce winter tires (this means that the same tire may be offered, simply void of the symbol). As time passes and tire molds are updated, all purpose-built winter tires are likely to feature the new symbol.
Winter tire sizing
Just replace using the same OE size, right? Not necessarily. Sure, you want to maintain tire load capacity, and you need to keep overall tire diameter as close as possible to the originals to prevent calibration problems with the speedometer, ABS and traction control system.
However, if your customer’s performance vehicle was originally equipped with low-profile, wide performance tires, they'll need to deviate from this in order to maximize winter traction.
A simple rule of thumb applies: You want the tires to float in sand, but you need them to dig in snow.
Digging requires a move to a narrower section and tread width. A wide tire is forced to "plow" through snow, while a narrow tire will slice through much more efficiently. Also, winter tires won't feature short and stiff sidewalls, since a greater degree of sidewall flexibility is needed.
For performance vehicle applications, this often requires a "minus-sizing" approach by either selecting a narrower "base model" size that was offered by the vehicle maker, or determining a proper alternate tire size (from a tire maker's sizing chart). Again, the goal is to select a narrower tire size that also maintains load carrying capacity and overall diameter.
While it may "go against the grain" of many performance-minded drivers who are accustomed to the wider-is-better approach, if they want to maximize performance in the winter, don't screw around. Sell them a set of purpose-built winter tires that will likely be narrower with a taller profile than their current skins.
Considering the incredible advances made by the leading tire makers in terms of winter tires, they'll never dread winter driving again.
Learning from experience: ‘I never once slid off my steering path'
I've experienced the benefits of purpose-built winter tires on numerous occasions. An excellent example was illustrated last winter during a horrific snow and ice storm in Northeast Ohio.
All of the vehicles along my path of travel (a combination of RWD, FWD and AWD, most of which were equipped with all-season or M+S tires) were either spinning their wheels or unable to climb even slight grades. While the vehicles were smacking into each other or sliding off the road, my wife's PT Cruiser (I get to borrow it on occasion) deftly trudged along without skipping a beat.
I don't recall any wheel spin, and I never once slid off my steering path during the entire 15-mile drive. The reason? I had recently installed a full set of known-brand dedicated winter tires.
The moral? Quality purpose-built winter tires will raise your customers’ confidence level dramatically. It's the difference between getting stuck or bending a fender, and making it home without incident. Once they experience a set of winter tires in slippery conditions, they'll never go back.
When narrow is better: 'Minus-size' during the changeover to winter tires
A quick look at The Tire Rack's sizing information provides some examples of why the size of the winter tire you sell may be different than that of the tire it is replacing. This is particularly true during a changeover from wider performance tires.
For example, a 2003 Lexus IS300 may have been equipped with 215/45R17 OE tires, but may offer a 205/55R16 alternative (a "minus-1" sizing move). That narrower 16-inch tire with the taller sidewall would be a better choice for a winter tire size.
Another example, using a "minus-2" move, involves a 2003 VW Jetta GLX VR6. If this car was originally outfitted with 225/45HR17 tires, a minus-2 move would result in using a 195/65R15 tire size. Again, a narrower tread and taller sidewall will maximize the benefits offered by purpose-built winter tires.
WINTER PERFORMANCE TIRES:Here's what a number of tire manufacturers offer in terms of winter performance tires:
Bridgestone Firestone North America LLC (BFNT) offers the Blizzak WS series, the Blizzak LM series, and the all-new Blizzak Revo 1.
The WS series -- which includes WS15 and WS50 models -- contains BFNT's multi-cell tread compound, which provides a large array of microscopic holes in the tread surface for better water pick-up.
The LM series is aimed at the high-performance and ultra-high performance applications. It contains a greater number of sipes, but not the multicell compound found in other Blizzaks. The compound found in the LM series is designed to remain soft under low temperature conditions.
The Blizzak Revo 1 contains the multi-cell compound found in the Blizzak WS series, plus an abrasive material that's mixed into the compound called "Particle X."
Particle X is comprised of microscopic particles that adhere into each microcell hole throughout the entire compound base. These particles "scratch" the road surface, providing superior ice traction.
In order to address vehicles that were originally equipped with "run-flat/zero pressure" tires, BFNT also has developed run-flat Blizzak winter tires.
Continental Tire North America Inc. (CTNA) offers six different winter tires: the ContiWinterContact TS810; ContiWinterContact TS810 S; ContiWinterContact TS790; ContiWinterContact TS790 V; Conti 4x4 WinterContact; and the VancoWinterContact.
The ContiWinterContact TS810 and TS 810 S both feature 20% wider sipes on their inner shoulders, plus new sipe spacers that prevent sipes from closing during surface contact.
The ContiWinterContact TS790 contains "revolutionary refined silica tread compound with Cross Link Sipe Technology," according to CTNA officials. It is available in 15-, 16- and 17-inch rim diameters and aspect ratios of 65 through 45.
The TS790 V is similar to the TS790, but comes with speed ratings of T, H and V. The TS790 S is offered in 17-, 18- and 19-inch rim diameters.
The Conti 4x4 WinterContact is offered in T, H and V speed ratings and is designed for "severe snow and ice winter conditions."
The VancoWinterContact contains funnel-shaped tread grooves, a high sipe density, a curbing rib and other features. The tire is offered in 15- and 16-inch rim diameters and only in 75- and 65- series profiles.
Goodyear Tire & Rubber Co.'s Eagle Ultra Grip GW3 utilizes V-TRED technology, which consists of V-shaped tread grooves.
The Ultra Grip GW3 also contains a 3-D bubble-blade block interlocking system and heavy sipes in the tread design to keep the tread face pliant in cold temperatures and evacuate icy water found just below snow.
The basic tread face for most Ultra Grip tires uses technology derived from Goodyear's European winter tires, according to Goodyear officials.
While Goodyear's Assurance with TripleTred Technology and Fortera with TripleTred Technology aren't true winter tires, Goodyear says they have many characteristics that are similar to winter tires.
Volcanic sand is used in the "Ice Zone" of these tires. As the tires wear, the sand creates microscopic cavities that work as tiny traction edges for better grip on slick surfaces.
The sand also is complemented by the use of glass fibers that form a pitted surface in the tread.
Also new from Goodyear is the Dunlop SP WinterSport 3D, which will be available in 22 sizes for the 2006-2007 winter season. The tire contains three types of sipes. Each is designed for changing weather conditions.
Toyo Tire (U.S.A.) Corp. offers its Observe studless winter radial tire designed for driving in severe weather conditions.
The Observe is speed rated Q, T or H (depending on size) and comes in 50- and 55- series aspect ratios. Sizes range from 175/70R14 to 225/50R17.
A recent addition to the Observe line is the Observe G-02 Plus unidirectional winter tire. Developed using Toyo's exclusive T-mode computer design technology, the Observe G-02 Plus improves both dry and wet handling in winter conditions, while reducing the audible tread noise sometimes associated with winter tires.
It sports a high-silica tread compound to help retain softness and performance in low temperatures, and sawtooth-shaped tread blocks for better acceleration and braking, say Toyo officials
The Observe G-02 Plus is available in 25 sizes, including 75 through 60 series aspect ratios.