It is a mechanical device which allows inflation/deflation and keeping the air inside an inner tube or tyre, in the case of tubeless tyres, under pressure.

A tread pattern design criterion on the basis of which elements of the same shape, but with different longitudinal dimension, are positioned in succession at a specific distances designed to reduce noise levels on a smooth road.

It is a tread design criteria according to which elements of the same shape but different longitudinal size are arranged in sequences to reduce the noise phenomena on smooth roads.

It is the sum of the rolling resistance of the tyres and the friction resistance in the rotating elements of the car (bearings and clutch up to the gears, excluding the engine).

Ratio between load and vertical deflection measured with the tyre not moving.