The inflation pressure of the tire generally impacts the rolling resistance, treadwear, handling and durability of the tire. Halobutyl rubber is the polymer of choice in the tire innerliner compound due to its excellent air and moisture impermeability and resistance to flex-fatigue and oxidative aging. The inflation pressure loss rate (IPLR) values measured following ASTM F- 1112-06 procedures have been shown to have an excellent correlation to the oxidative aging of the natural rubber wire coat compound and to the durability of passenger tires when tested on a 1.7-m laboratory roadwheel. Experimental passenger tires previously were made with innerliner compounds having varying amounts of bromobutyl rubber (BIIR) and natural rubber and, are now made with varying innerliner thicknesses. Tire performance is related to bromobutyl rubber level and to cured liner gauge.