I called my friend Jay Nobles who owns Nobles Tire Service and has 30 years experience in the tire business. He told me that they can smell a Zippered tire (after examining it) when the customer drives up, and they will REFUSE to air up that tire. He agreed with the 20% rule about running a tire low and said if a person knows that the tire has been run low DO NOT AIR IT UP. He says that after it cools down an experienced tire mechanic can add about 30# and listen for hissing - that indicates a Zippered tire. If you hear this hissing DO NOT ADD MORE AIR - CHANGE THE TIRE!
Jay said that customers think that he is just trying to sell them a new tire but a Zippered tire is nothing to fool around with!
Tuga & Karen Gaidry
2012 Honda Pilot