Ever wondered why wheels don't come in different shapes? Such as why you can't simply pick up square- or triangle-shaped wheels from your local wheel shop? Well, we are going to answer that specific question in today's blog post.
The circular shape of wheels and tires ensure that the vehicle can move fast. Wheels help the car move by rolling smoothly and without much drag. Their circular shape is the most appropriate one as they maintain a uniform and smooth contact with the surface. This constant contact with the road surface provides the wheels and tires with grip and traction that other shapes just can't.
Any other shape other than round, such as triangular, square, or rectangular, has edges that would dig into the road. This would make the vehicle rather slow; not to mention they would increase the rolling resistance.
As rolling resistance increases, fuel consumption by the engine increases too. It is, therefore, in our wallet's best interest to get the least amount of rolling resistance. The smaller the number of sides a wheel has, the greater the rolling resistance. Triangular and square wheels would cause the engine to severely consume more gasoline because of the sharp edges. These edges would dig into the road surface and require extra energy to "undig" themselves out. As a result, a wheel's circular shape offers the least amount of energy loss when converting rotational energy to kinetic energy.
By definition, a circle is an infinite number of points equal in distance from a center. Wheels and tires use the same logic to smoothly and comfortably roll on the road surface. The lug nuts and bolts are tightened around the center of the wheel allowing for uniform movement.
With non-circular wheels, the car would jolt up and down because the edges and flat sides of the wheels would be of different distance from the wheel's center. This would create an extremely bumpy and uncomfortable ride. The suspension would help with some of the movement, but it just won't be enough.
If you would like a visual representation on precisely why square wheels are not used, check out this funny Mythbusters video!