Originally Posted By: BHopkins
Tire manufacturers do not typically sipe tires because of the expense. Siping cannot be done in the mold. To create grooves in the mold, rubber has to be displaced. In the case of siping, the sipe, or cut, does not remove any material. Thus, the tire manufacturer has to use a secondary process to sipe tires. And there is the added expense. Typically, the only tires that come siped from the factory is winter snow tires.
The science behind siping is very well established. There are a number of advantages to siped tires, including improved braking and better traction.
Be very careful here. The term "sipe" is being used for 2 very different things - although the end result is close to being the same.
In tire manufacturing, there are thin blades put in the mold to create an edge. Both the blade itself and the resulting gap are both called "sipes". The term is also used when a knife is used to cut cross ways through the tread of a finished tire and the result is a disconnected bit of tread rubber but with no gap. I'm going to refer to the second process as "aftermarket siping" to distinguish between the 2.
What do sipes do? They provide an edge, which has traction advantages when the traction is being generated by the paddle wheel effect - wet and snow. They also tend to break up the surface tension of water, making it easier to reach the textured pavement.
But that edge comes at the cost of movement - which results in less dry traction, more rapid wear, more heat generation, less fuel economy, etc. Much of the advertising for the process either glosses over these, or flat out lies about it.
Any time a tire is altered, the warranty is void. Therefore adding a while sidewall inlay or aftermarket siping a tire has a certain risk. While most tire manufactures will accept a warranty claim for an aftermarket siped tire for unrelated issues, they will not accept a warranty claim if the process is potentially the cause.
- and, Yes, there are problems that aftermarket siping causes. Rapid wear, irregular wear, structural failures are examples of things that would cause the tire manufacturer to reject a warranty claim.
