The invention relates to a tire of a structural combination of tire
tread and sidewall components with compositional limitations containing minimal, if any, of in situ formed
alcohol and
methyl isobutyl ketone byproducts. The
tread component rubber composition contains pre-hydrophobated silica reinforcement. The sidewall component contains low unsaturation EPDM or brominated
copolymer of
isobutylene and p-methylstyrene and may contain pre-hydrophobated silica reinforcement. The silica reinforcement for said
tread and sidewall components is a pre-hydrophobated
precipitated silica. The pre-hydrophobated silica is prepared, prior to mixing with the
elastomer(s), by reacting hydroxyl groups (e.g.
silanol groups) contained on the surface of a
precipitated silica with an alkoxyorganomercaptosilane or a combination of an alkoxyorganomercaptosilane and a substituted alkylsilane or with a bis-3(trialkoxysilylalkyl)
polysulfide which contains an average of from 2 to 4 connecting
sulfur atoms in its polysulfidic bridge to form a composite thereof. The
alcohol byproduct therefrom is removed from the composite prior to its introduction into the rubber composition(s). In another aspect of the invention, the connecting sidewall rubber composition, and optionally the tread composition is free of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine antidegradant (referred herein to as 6PPD) in order to prevent in situ formation of
methyl isobutyl ketone byproduct from the reaction of 6PPD with
atmospheric oxygen and / or
ozone.