Knowing your tires
When changing or buying car tires it is important to have a little knowledge on what tread designs tell about the tire’s characteristics. Knowing about what particular tread designs will help you understand how the vehicle will perform in the road surface. So depending on what kind of performance or usability you want for the car, you need to keep this in mind.
The tire tread is the area that touches the road surface. Let’s have a look at the different tire patterns below.
Directional or Unidirectional, usually V pattern, pointing in one direction.
Symmetrical tire pattern
So what do these tire tread tell about the tire? It’s very simple. In directional or uni-directional (which means the tire tread is pointing in one direction), tires point forward. These types of tires are better for wet grip and are sportier than usual passenger car economy tires. These type of tires since they arrow and point in one direction, they cannot be mounted from left side of the vehicle to the right and vice versa. Because by doing so, you would be changing the direction it was pointing. The uni-directional tire tread pattern will always point front of the car or forward. Suppose you are standing at the back of the car, and you look at the rear tires, the arrows would be pointing upwards and if you are standing in front of the car and looking at the front tread pattern, the arrows would be pointing down. The easy way to understand this is to do it practically and see if you can match the explanation rule. Usually these tires have a writing saying “outside” and “inside” on the side walls. If it’s too complicated for you to understand just follow the writing and mount the tire on the rim matching the writing. Inside side would be on the inside side of the rim and outside side would be on the road side of the rim.
Symmetrical tires (see above photo; symmetrical tire pattern) have tread patterns that are symmetric. This means no matter which side of the wheel (front to back) (left to right) (front left to rear right) you replace the wheel; the pattern being symmetric does not have any effect on the tread direction since it’s symmetric.
Asymmetric tires are similar to directional or uni-directional tires and they can only be rotated front to back just like directional tires. These tires are a mixture of both sporty performance and regular passenger usability performance in city roads. They will also have the writing instruction of outside and inside on the side wall. Asymmetric tires have some v pattern directional treads as well as non directional treads. In the diagram below you can also see the writing written outside and inside.
The picture below identifies the parts of an tire that is important in determining the type of tire.
The zigzag grooves & blocks towards the middle or inner side of the tire comes in aid of dispersing water, while the outside shoulder area comes in aid of gripping the asphalt when the tires are turning for cornering. So from a logical viewpoint, the race spec tires will have much meatier, or wider shoulder grip surface area for better cornering ability along with beefier sipes for inside grip and water dissipation. Likewise the blocks and ribs would also aid in having better braking performance and as well as acceleration performance in straight lines.
In this above photo, Tire A seems to have a larger rubber surface area compared to B C D. Tire A is more of a track based, race spec tire. These tires have exceptional cornering gripping acceleration and braking performance on track. But they won’t last very long on city or regular road surfaces. Because of their wider meatier rubber surface area, on city or regular uneven roads, the tires will get worn and torn faster than road going passenger tires.
Tire B is a directional tire. It is a perfect mixture of good grip sporty performance and a blend of regular road gripping ability. The inner tread pattern disperses water well while the outside shoulder has substantial surface area for better gripping and performance.
Tire C is an asymmetric tire. It is a mixture of directional and symmetrical tire. The mounting process of this tire is similar to Tire B (directional tire) as discussed previously. If you want regular road performance with comfort and occasional spirited driving then this is an ideal tire. It is also a cheaper alternative to A and B. Nowadays most car manufacturers fit the cars with asymmetrical tires.
Lastly Tire D is symmetric, meaning the tire can be rotated to be mounted in any direction. From left to right left to rear right and vice versa. Whichever way the tire is rotated and mounted on the rim, there won’t be any change in pattern that is coming in contact with the road surface.
Now that you have known about different tread patterns and the types of tires, it might be difficult to grasp as to what the rotational changes will be. It is not easy to visualize how the pattern will change or reflect when the tire is rotated. The easy way you can do is to try in your own car, match the specs. If its too difficult then the manufacturer has already denoted the instruction on the side wall with rotational arrows directions. Or you can sketch up a patter on a paper and try rotating the image as an example to rotating the tires from left to right in real life. Only then you can visualize and know how the tread pattern is changing with every rotation.
Now that we have done our homework on different tread pattern styles, lets discuss what tread pattern relates to what type of performance. Just for an practical example, if you look at very expensive race spec or track spec tires, you would easily find the difference with regular road going tire tread patterns.
From the above pictures, left to right to bottom ( Pirelli P zero, Advan Neova AD08, Dunlop SP sport).
All these tires are used in various road and sport cars. Since we have discussed how to identify the performance by the tread pattern you would easily be able to tell that the P Zero Michelin, is for high horsepower race car application while the Dunlop being the most economical practical road going passenger vehicle application. The Advan Neova being a track spec tire.
So which tire is right for you?, Well, you would be able to answer that now. You need to ask yourself what kind of driving you would be doing with the car, what’s the condition of the road in your city or country?, What kind of power your car is making? What kind of performance you desire?. Note that high performance race spec or track spec tires are not just about the design. It is the material that the manufacturer is using that also determines its performance and durability in the long run. Race spec or track spec tires need a lot of warm up before they can grip the road with full potential. On the other hand, road going tires may heat up a lot under hard cornering and a lot of braking and will give way with grip.
So choose wisely, before buying tires and rotating them.
image and info sources: google, pepboys.com, bestonetire.com, pakwheels.com , superstreetonline.com, tires.canadiantire.ca/