As I am now shopping to replace mine, I have just read what they really say 'on the box'. May put things in to perspective:
The P Zero Corsa is Pirelli's DOT-legal Competition tyre primarily developed for use on high performance cars at drivers' schools and lapping days conducted on race tracks. The P Zero Corsa incorporates Pirelli's racing experience to enhance driving satisfaction at the limits of performance.
On the outside, The P Zero Corsa uses a high hysteresis tread compound that transfers the vehicle's horsepower to a dry track by developing inspiring grip at high tread temperatures. This tread compound is molded into a unique asymmetric and directional tread pattern that features a sturdy outer shoulder to provide lateral stability and cornering grip, while grooves in the tyre's central and inner tread areas enhance wet track handling and braking. The P Zero Corsa's asymmetric and directional tread design requires separate "left" and "right" side tyres for the vehicle as branded on each tyre's sidewall. On the inside, the P Zero Corsa features highly flexible steel belts reinforced by spirally wound nylon to enhance steering precision and provide high-speed capability while reducing weight.