Car tyre

A car tyre having a tread comprising a central portion located across an equatorial plane, a first shoulder portion located towards an outer side of the tyre and a second shoulder portion located towards an inner side of the tyre, the central portion being separated from said shoulder portion by two first circumferential grooves having a respective minimum width of about 5 mm, wherein:

• said first shoulder portion and said second shoulder portion comprise a plurality of first transverse grooves having a first end located substantially at a respective edge of the tread, having a width greater than or equal to about 4 mm and an axial extension equal to at least 50% of the width of the shoulder portion in which they are located;
• said two first circumferential grooves are a first circumferential groove facing towards the outer side of the tyre and a first circumferential groove facing towards the inner side of the tyre;
• the number of said first transverse grooves of the first shoulder portion is lower than the number of said first transverse grooves of the second shoulder portion;
• said central portion has two circumferential ribs, a first and a second circumferential rib respectively, comprising a plurality of second transverse grooves;
• said central portion comprises one second circumferential groove so as to define said first and second circumferential ribs
• said first circumferential rib being axially delimited by the first circumferential groove facing towards the outer side of the tyre and the second circumferential groove, said second circumferential rib being axially delimited by the first circumferential groove facing towards the inner side of the tyre and the second circumferential groove;
• said second transverse grooves have a maximum width smaller than or equal to about 3 mm and define in said at least one circumferential rib a void-to-rubber ratio smaller than 0.06.