A pneumatic tyre for a car having a tread, including a central portion disposed astride an equatorial plane and two shoulder portions. The central portion is separated from the tread shoulder portions by two circumferential grooves and at least one circumferential row, included between a first and a second circumferential groove, is present in the central portion. The tread has a hollow/solid ratio lower than 0.28. The circumferential row comprises transverse grooves extending over at least 80% of the width of the circumferential row. Each transverse groove includes a median line having at least one first rectilinear stretch and one curvilinear stretch. The transverse grooves have a smaller width than that of the circumferential grooves.