As to slow leakage:
Do you have a tire pressure monitoring system installed?
The kind that screw on the rubber valve stems are NOTORIOUS leakers.
At speed, the stems bend down to ride on the rim breaking the seal at the wheel. Steel or brass shanks (the 100 PSI type) do NOT bend and do not leak.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW