Pirelli Rally Tire Information
Pressure
Working pressure values depend on the size of the tire in relation to the load that it is subjected to. In other words, it will vary according to the type of car, the weight and conditions of use.
In particular, as the weight of the vehicle, speeds and accelerations that the tire is subjected to increase, the working pressure must be increased. In any case, tires should not be used at pressures below 1.6 bar (24psi).
Using excessively low pressures would bring about the breaking of the tire due to excess force on the sidewall or unseating from the rim. “Hot” working pressures are usually in the range of 2.2 – 2.5 bar (32-36psi).
Initial inflation pressures vary in order to obtain these values, depending on whether the tires are preheated or used “cold”. Indeed, preheated tires can be inflated to slightly lower values than cold tires.
The difference will depend on the type of heater, the time it remains and the environmental conditions.
Tread hand-cutting
The tread on some types of tires can be hand cut to increase the size of the existing grooves.
Hand-cutting is useful for improving grip in certain intermediate situations, between dry and thoroughly wet surfaces, or on mixed gravel/rock and sandy surfaces.
The tread efficiency in the conditions for which it was originally designed will no longer be the same.
Hand-cutting must be carried out by experts using special equipment, suitable for use while observing safety regulations.
The colors are used to highlight where grooves can be hand-cut.
Gravel grooves
