The invention relates to a tire having a rubber tread comprised of
cap/base construction where the tread cap layer is the load-bearing
running surface of the tread having a lug and groove configuration and
the tread base layer underlies the tread cap layer wherein the base layer
is a transition zone between the tread cap and remainder of the tire
carcass and is not intended to be a running surface of the tread. The
tread cap layer is comprised of three distinct load-bearing zones, namely
a circumferential annular central rubber zone positioned between two
lateral and peripheral circumferential annular rubber zones, each zone
extending from a tread base carbon black-rich rubber composition to and
including said tire tread running surface, wherein the rubber
compositions of each of said zones contain both carbon black and silica
reinforcement. In one aspect, said central zone is of a silica-rich
rubber composition and said lateral zones are of a carbon black-rich
composition. In another aspect, said central zone is of a carbon
black-rich rubber composition and said lateral zones are of a silica-rich
rubber composition.