Confirmed one of my bridgestone all season is leaking 8 lbs of air a day. I dont see anything obvious so im gonna drop it off at costco for inspection on the tire.
How about the valve core? Maybe spray a bit of soapy water on there and look for bubbles.
If so, it's cheap and easy to tighten and/or replace. Could save you the hassle of a Costco trip.
Also, on an aluminum rim, make sure they use bead sealer. maybe they all do now but when I worked in a tire shop, some did, some didn't. The some that did usually only if the customer specified and/or had a history of slow leakage.
I suspect some of the guys tried to skip it because some shops pay piece work so the faster you can get it done, the more cars you can do.Myself: I sealed every rim I did, no exceptions. Take the tires off. Put the rim on the balancer, run the balancer and clean the bead area with sand paper then reseal with sealer and back together. maybe it took more time but it would take even more if the customer had to come back and have it done all over again because I was in a hurry.