invention were more uniform than standard whitewall tires for example they possess better balance from side to side the removal of standard white sidewall compounds also eliminates problems associated with modulus transitions due to widely different compounding materials within the sidewall construction the potential for the white splice in standard whitewall tires to open during curing and consequently causing a defect was also eliminated misalignment of the white sidewall material relative to the mold groove is a frequently encountered problem in conventional techniques for building whitewall tires which is also eliminated a blend containing 50 weight percent spbd and 50 weight percent rubbers was prepared the spbd which was utilized had a melting point of 123 u00b0 c the rubber component utilized in the blend contained 60 chlorobutyl rubber 35 natural rubber and 5 epdm rubbers the blend prepared also contained about 1 phr of an antioxidant about 15 phr of titanium dioxide a white pigment about 0 5 phr of stearic acid about 3 75 phr of zinc oxide about 0 9 phr of sulfur and about 1 16 phr of an accelerator it should be noted that the spbd utilized in accordance with this invention is a crosslinking thermoplastic resin and is considered to be a rubber in calculating phr parts.