I've NEVER had a situation where I could not find it w/ soapy water. I checked tread, beads, sidewall, valve stem and the core. Not a sign of a bubble at 40PSI. The tire certainly is slowly leaking at about 3 psi a week. The only thing I can think of is a porous barrel. Is that a thing on jeeps by chance? I have a 2016 back country w/ the OEM black rims. I noticed that this particular rim does NOT have the jeep painted in it and is a slightly glossier finish but it is a jeep OE wheel... Anyone ever have a slow leak and couldn't find it?