TYPES OF TIRES

Vehicle applications

The vast array of available tires can be confusing, if not overwhelming, for those of us with even a relatively solid understanding of the tire industry. The tire manufacturers try to make the process of seeking new tires more streamlined for us by classifying tires into several standard types, based upon the type of vehicle. The tire manufacturing process, equipment and raw materials differ according to the type of tire, therefore it’s very common for tire manufacturers to specialize in more than a single tire type.  Let’s take a closer look at the different Tire Classifications or Tire Types:

High Performance

High Performance tires are just that – tires which are designed to be used at higher speeds while offering a more sporty driving style. High Performance tires feature a softer rubber compound designed to improve traction, particularly when cornering at high speeds. Of course, there’s no such thing as a free lunch. The trade off of the softer rubber is shorter tread life.

High Performance tires can sometimes sacrifice wet or adverse weather handling due to their shallower water channels (or grooves). They are constructed this way in order to maximize the rubber tread surface area for dry weather performance. The goal is to have a greater portion of the rubber tire in contact with the road. The ability to provide a high level of performance on both dry and wet pavement varies significantly among tire manufacturers, and in fact, even among tire lines (models) of the same manufacturer. This is specifically an area of active tire research and development, as well as marketing.

Mud and Snow

Mud and Snow tires, noted by the term M+S, M&S or M/S, is a classification for what’s commonly known as winter tires. Mud and Snow tires are designed to provide improved performance during conditions that one would encounter when driving in adverse weather conditions and low temperatures. The tread compound of Mud and Snow tires is usually softer than the tread compound used in tires for summer conditions. This provides better grip on ice and snow, but wear more quickly at higher temperatures. Also, Mud and Snow tires may have well above the average number of sipes in the tread pattern to grip the ice.

What is Tire Siping? This is the process of cutting small slits, or grooves, into the tread blocks of tires in an effort to provide better traction. The sipes allow the tread blocks to spread on contact with the ground, which assists in expelling water from the tread while providing better grip. You can rest assured that nearly every All-Season, Mud and Snow, and All-Terrain tire marketed today is siped in the factory mold.

Winter-only tires, as designated by the American Society for Testing & Materials, will be indicated as such on the tire by a Mountain/Snowflake emblem or pictograph.

Some winter tires may be approved for the installation of metal studs to provide additional traction on icy roads. The studs also serve to roughen the ice which provides better friction between the ice and the soft rubber in the winter tires. Generally speaking, studs are never used in heavier vehicles. Note that the use of studs is regulated in many countries. In fact, it’s even prohibited in some areas due to the increased road wear, and thus required road repair, caused by the studs. You’ll find studded tires more commonly used in the upper tier classes of ice racing and rallying.

Some winter tires are designed for traction on ice but are not studded. These may use a hydrophilic rubber which adheres to the wet film on the ice surface.

On some occasions, a particular area may mandate the use of snow tires or a traction aid such as a tire chain. If you’ve ever driven to Lake Tahoe during a snowstorm, Caltrans (California Department of Transportation) will maintain check points and not allow you to proceed without snow tires or tire chains.

Mud-only tires also exist. These are specialty tires with large, chunky tread patters intended to bite into surfaces of mud. By design, mud tires allow the mud to clear quickly from between the lugs. In order to spread the weight of the vehicle over a wider surface area, mud tires are often wider than other tires. This is important to ensure that the weight of the vehicle does not provide for it to quickly sink into the mud.

In more reasonable amounts of mud (or snow), thinner tires should be used. By virtue of having a smaller surface area in contact with the terrain, these tires will have more pressure on the road surface. This allows the tire to more easily penetrate the mud (or snow) layer, thus providing better grip. Of course, this logic is thrown out the window if the snow is too deep to allow for such penetration.

All Season

All Season is a tire classification which essentially serves as a compromise between tires developed for summer driving and tires intended for use under winter conditions. For scientific reasons, the type of rubber and the tread pattern best suited for use under summer conditions is not capable of providing reliable performance on snow and ice. The All-Season tire represents a mixture of both. That being said, it’s important to note that the All-Season tire is neither an excellent summer tire nor an excellent winter tire.

Consumers love the all-season tire and as a result, they can be found literally just about everywhere. All-Seasons are commonly used as original and replacement equipment on automobiles throughout North America and Europe due to their convenience and adequate performance in most driving conditions.

All-Season tires can also be marked for mud and snow, but even so they’ll rarely have the Mountain/Snowflake emblem branded onto their sides. Keep in mind that an All-Season tire marked for mud and snow will most likely have poorer performance than a typical Mud and Snow tire.

All Terrain

All-terrain tires are commonly found on light trucks and sport utility vehicles (SUVs). All-terrain tires usually have stiffer sidewalls which allow for greater resistance against punctures when traveling off-road. The tread pattern often contains wider spacing than All-Season tires in order to expedite the removal of mud from the tread. The majority of All-terrain tires are intended primarily for on-road use; this includes any which are original equipment.

Spare

Many vehicles carry a spare tire which is already mounted onto a wheel. Obviously, the spare tire is intended to be used as a temporary replacement in the event of a blowout or flat tire. However, if the spare tire is of the same size and type as your other 4 tires, it can be put into regular use when your rotate your tires.

Mini-spares or space-saving-spares are also very commonly used spare tires. These are smaller than normal tires in order to save on cost, weight, gas mileage and the space required for mounting and storing. Mini-spares have a short life expectancy and relatively low speed rating. They are intended for emergencies and should be used under those circumstances only.

Run Flat

Modern technology has allowed for the development of many innovative tire designs. Among those are Run-flat tires, which actually permit the tire to run safely with no air for a limited number of miles at a limited speed. These tires usually feature strong, load-supporting sidewalls.

The major disadvantage to Run-flat tires is that they are not allowed to be repaired when and if a puncture occurs. This is due to a warning issued by the tire manufacturers regarding the inability to determine the condition of the sidewall. After the puncture, the sidewall compacts rendering its state of condition unknown.

Motorcycle

There are several different types of Motorcycle tires. Let’s examine the most common types offered:

• Sport Touring – ideal for long straights, highways, and riding across the country. They’re generally not used for high cornering loads.
• Sport Street – terrific cornering tires, these tires are optimal for aggressive street riders. In lieu of being a longer lasting tire, Sport Street tires offer better traction during high speed cornering. Street and Sport Street tires have good traction when cold, but if warmed too much they can actually lose traction as their internal temperature rises.
• Track or Slick – these tires are intended for races or tracks. Track or Slick tires, also known as Racing Slicks, actually have more of triangular form which allows for a larger contact patch when cornering. However, the trade off of the triangular form is a smaller contact patch in the center, which causes the tire to develop a flat spot more quickly when riding on long straights. A center flat spot has almost no tread and therefore becomes dangerously slick in wet conditions. Racing slicks are also made of harder rubber compound and therefore need to be warmed to a higher internal temperature than street tires in order to provide similar traction. However, most street riding will not create a significant amount of friction to maintain the slicks optimal (and higher) temperature, particularly in colder climates or when riding in the spring or fall. It might not be a surprise to learn that these tires are known to have a shorter street life and are not recommended for street use by manufacturers.

 

Tags: Tires