Abstract: A halobutyl rubber is generally used in the innerliner of pneumatic tires to retard the escape of air used to inflate the tire, thereby maintaining tire pressure. Since halobutyl rubbers, such as bromobutyl rubber, are generally the most expensive elastomers used in tires, it is desirable from a standpoint of cost reduction to reduce the level of halobutyl rubbers used in tires. The present invention relates to a technique for reducing the quantity of halobutyl rubber utilized in the innerliner of tubeless pneumatic vehicle tires. The present invention more specifically relates to a tire innerliner and pneumatic tires containing the same, which are prepared from a composition comprising, based on 100 parts by weight of rubber, a blend of (1) about 50 parts to about 90 parts of a halobutyl rubber and (2) about 10 parts to about 50 parts of a styrene-isoprene-butadiene terpolymer rubber having a first glass transition temperature which is within the range of about -110.degree. C. to about -20.degree. C.