Pneumatic tire

A pneumatic tire comprising:

• a tread portion being provided with at least one circumferentially and continuously extending main groove and at least one land portion adjacent to the main groove;
• the land portion being provided with a plurality of lateral grooves extending across the land portion;
• each lateral groove comprising a main portion having a width equal to or more than 2.0 mm and a bottom, and a sipe portion having a width smaller than the width of the main portion and extending radially inwardly from the bottom of the main portion;
• the main portion comprising a first wall located on a first side in a circumferential direction of the tire and a second wall located on a second side in the circumferential direction of the tire;
• the sipe portion comprising a first sipe wall located on the first side and a second sipe wall located on the second side;
• the lateral grooves comprising
• a first lateral groove having the first wall being continuous to the first sipe wall smoothly so as to form a single plane wall and the second wall connecting to the second sipe wall in a step manner,
• a second lateral groove having the second wall being continuous to the second sipe wall smoothly so as to form a single plane wall, the first wall connecting to the first sipe wall in a step manner;
• and
• the first lateral groove and the second lateral groove being arranged alternately in the circumferential direction of the tire such that the first lateral groove second wall and the second lateral groove first wall alternate in the circumferential direction of the tire,
• wherein the at least one main groove comprises a pair of crown main grooves to form a crown land portion therebetween on a tire equator and at least one middle land portion disposed axially outward of one of the crown main grooves, the lateral grooves comprise a plurality of crown lateral grooves on the crown land portion and a plurality of middle lateral grooves on the middle land portion, each of the middle lateral grooves curves has an arc shape in a plan view of the tread portion, and a center of curvature of the arc shape is located on an inner region which is an inner half region of the middle land portion in an axial direction of the tire.