I've had a EaA123 for about 4 years now. I plan on changing it this winter after my current PureOne A/F has 20K on it. The filter will be about 5 years old by then. I emailed Amsoil's tech support asking the shelf life of these filters and received a very vague answer from Amsoil... "We do not limit the shelf life of the EaA filters." Byron Selbrede Technical Services I'm sure there is some kind of shelf life on these filters. I would like to know how long? I've seen these foam type sealing gasket become brittle on some old air filters. Anyone?