Radial pneumatic light truck or automobile tire

A tread for a pneumatic light truck or automobile tire, the tread when incorporated in the tire having an axis of rotation, a pair of lateral edges, a tread width defined as the axial distance between lateral edges, and an equatorial plane perpendicular to the axis of rotation and spaced equidistant form the lateral edges, the tread comprising:

• tread base;
• a plurality of traction elements extending outwardly from the tread base to a radially outer road contacting surface;
• a plurality of circumferentially continuous grooves including a first and a second circumferentially continuous wide grooves, the first and second wide groves each having circumferentially continuous windows extending from the tread base to the radially outer road contacting surface, wherein the tread when attached to a normally inflated and loaded tire and when viewed in plan or frontal view displays the windows, in the ground contacting portion of the tread, each window having a shape that is triangular or trapezoidal having two sides and a radially outer long base, each of the long bases having an axial width of 7% to 20% of the tread width, the first and second wide grooves dividing the plurality of traction elements into three distinct tread zones including a first zone, a second zone and a third zone, the first zone being located between the first and second wide grooves and axially defined as the axial distance between two planes, one each plane passing through the intersection of a long base and an axially adjacent side of a window of a respective wide groove, the second zone being located between the first lateral edge and a plane passing through the intersection of the long base and axially adjacent side of the window of the wide groove and the third zone being located between the second lateral edge and a plane passing through the intersection of the long base and the axially adjacent side of the window of the second wide groove, the first zone having a net-to-gross ratio measured around the entire circumference of the tread greater than 90% of the net-to-gross ratio of the third zone and less than the net-to-gross ratio of the second zone;
• a plurality of lateral grooves, the plurality of lateral groves in combination with the circumferential grooves define the traction elements, one lateral groove intersecting one circumferentially continuous wide groove at each amplitude peak of the zig-zag portion on each side of the one wide groove, the amplitude peaks being the axially outermost locations of the zig-zag path as measured on either side of the one wide groove;
• and
• wherein each traction element adjacent the one wide groove has a straight edge and a portion of the traction element protruding into the one wide groove from the straight edge, the straight edges on one side of the one wide groove being aligned along a first line which extends in the circumferential direction, and the straight edges on the other side of the one wide groove being aligned a second line which extends in a circumferential direction, the axial distance between the first line and the second line defining the long base of the window.