Pneumatic radial tire tread pattern

A pneumatic radial tire having an equator comprising:

• a carcass including at least one ply having cords disposed substantially radially of the tire;
• a reinforcing belt extending substantially circumferentially of the tire over said carcass;
• a tread portion, including shoulder portions, of elastometric material over said carcass;
• and outer shoulder and sidewall portions of elastomeric material over said carcass, said tread and outer shoulder portions comprising similar circumferentially overlapping patterns, each pattern having lugs and grooves and having a first tread lug at the equator of the tire and having four similar tread lugs of different shape from said first lug, first tread lug has a shape of a polygon having opposite sides parallel and substantially equal in length, wherein said different shape of said four similar tread lugs is a polygon having sides unequal in length, each of said four similar lugs having its longest side substantially parallel to the longest side of said first lug, wherein said four similar tread lugs surround said first tread lug, a first pair of said four similar lugs being adjacent a second lug at the equator in a second of said overlapping patterns and each of said first pair of said four similar lugs having its longest side substantially parallel to the longest side of said second lug, said first pair of said four similar tread lugs separating said first tread lug and said second tread lug along the equator, wherein said second tread lug is of substantially the same shape as said first lug, and a second pair of said four similar lugs being adjacent a third lug at the equator in a third of said overlapping patterns and each of said second pair of said four similar lugs having its longest side substantially parallel to the longest side of said third lug, wherein said first and second pairs of said four similar tread lugs surround said second tread lug, said second pair of said four similar tread lugs separating said second tread lug and said third tread lug along the equator, wherein said third tread lug is of substantially the same shape as said first lug.