So why are my car tires so wide? It’s not a sports car.


Some of the complaints I’ve heard; Wider tires are usually more expensive, don’t always ride as nice and seem to wear out faster. The answer I found was not what I expected.

It is true that wider tires commonly have better traction. The main reason why this is  does not relate to contact patch, (surface area making contact to the road ), but to composition. Soft compound tires are required to be wider in order for the side-wall to support the weight of the car; softer tires have a larger coefficient of friction, (better traction). A narrow, soft tire would not be strong enough, nor would it last very long. Wear in a tire is related to contact patch. Harder compound tires wear much longer, and can be narrower but have less traction. Among tires of the same type and composition, there is no appreciable difference in ‘traction’ with different widths. Wider tires, assuming all other factors are equal, commonly have stiffer side-walls and experience less roll. This gives better cornering performance.

Friction (traction) is proportional to the normal force of the asphalt acting upon the car tires. This force is simply equal to the weight which is distributed to each tire when the car is on level ground. For a wide tire, the area is large but the force per tire contact area is small and vice versa. The force of friction is therefore the same whether the tire is wide or not. However, asphalt is not a uniform surface. Even with steamrollers to flatten the asphalt, the surface is still somewhat irregular, especially over the width of a tire. Drag racers increase the likelihood of making contact with the road by using a wider tire. In addition a secondary benefit is that the wider tire increased the support base and makes it hard to turn the car over in a turn or in a mishap. 

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My take on this information: The wider tires give better cornering (stability) on our lighter/narrow cars and can help in preventing a roll over. Read as Safety.

What was the surprise message relating to the width of a tire verses traction?

If you have some other opinion or ideas, feel free to share in a reply to our email or on our Facebook page.

As always Great Service With A SmileEmoji

Last week I asked: What do you think caused the water build up in my trucks engine?

The answers are in the article; short hop driving in cold, washing the truck in a warm garage, and not changing the oil after winter. An engine can operate at temperatures exceeding well past 210 degrees and will evaporate moisture in normal usage. As stated, my truck does not go through normal usage. I was lucky this time and don’t plan on pushing that button again. Thanks for reading.