tire with a multi-layered tread

The invention relates to a tire having a rubber tread (1 ) of a cap/base configuration composed of a composite of a silica-rich tread cap layer (4) running surface, and an underlying transition zone composite of a carbon black-rich intermediate layer (6) positioned between the tread cap layer (4) and a tread base layer (5). The combination of intermediate layer (6) and base layer (5) provide a beneficial graduated stiffness bet-ween the tread cap layer (4) and the tire carcass (7). Significantly, the transition zone composite enables a significantly thicker carbon-black rich portion of the tread compo-site and an associated thinner silica-rich tread cap running surface. In one aspect, the intermediate layer (6) of the transition zone composite can extend to and include a bottom portion (8) of at least two of the grooves (3) of said tread cap layer (4) to support an associated tread lug (2) therebetween.