Do Wider tyres Have More Grip On The Road Or Is This Just A Myth?

One of the most important parts of any car, be it a car, truck or Sports Utility Vehicle is the tyres.

One question with regards to tyres has been widely debated, there are plenty of articles and videos discussing whether or not having wider tyres provides more grip. It’s commonly believed that having wider tyres provides more grip on the driving surface, but according to a video posted by Jason Fencke of Engineering Explained, wider tyres do not necessarily mean more grip.

The video shows 27 different trucks and sports utility vehicles being tested and the results give us a clearer answer. The type of tyre is much more important than the width. The main reason why this is so does not relate to contact patch, however, 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, therefore 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. They do, however have a lower coefficient of friction, therefore less traction.. Wider tires, assuming all other factors are equal, commonly have stiffer side-walls and experience less roll. This gives better cornering performance.

Friction 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. Force can be stated as Pressure X Area. For a wide tire, the area is large but the force per unit 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.

Drag racers can therefore increase the probability or 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.