Siping uses thin, razor like blades to make cuts, or slices in the tread without removing rubber.
The thin cuts can be made side-to-side, across the face of the tire or around the circumference of the tire.
Because a tire constantly flexes when under load, siping will help the tire build heat quicker and get it to the optimum operating temperature sooner.
Additionally, when the tire is warm, siping will also allow it to dissipate heat when the cuts open up.
Removing heat may make it more difficult on re-starts but it will reduce the chances that a tire will blister.
You’ll want to use a heated siping tool as they allow the blades to cut smoother and more accurately.
It’s a good idea to use your Tread Depth Gauge to make certain that you never sipe a tire more than half the depth of the tread block. If you cut the tires too deep, the sipes may cause the tire to rip or chunk.