Special tire valves?

Tires have been a headline issue in racing the past several weeks, and the latest twist concerns not the rubber or construction design but rather with the air-pressure valve. Some team engineers say they suspect rival teams of using special valves designed to bleed off excessive air pressure, to keep the tire at a constant pressure. That could be a significant advantage, because tires will typically build up as much as 16 psi over a 100-mile run, and tires with higher pressure handle much differently in corners. Such bleeder valves aren't new in racing, of course; however technology today could make such special valves virtually impossible to distinguish from ordinary valves. Winston Salem-Journal