<nerd alert>

I'd say 1psi per month is normal assuming constant ave temps. A drop from 40 to 20 degrees would also give a 1-2 psi drop as well. Depends on tire internal volume and pressure

Reason you lose pressure while sitting (assuming no pressure drop) is because air is 78% nitrogen and a balance of trace gases (Oxygen, helium, etc). The smaller trace gases can escape easier through pores in the rubber, so that's why tires lose pressure over time.

Filling the tires with 100% nitrogen can help slow leaks waaaaaay down due to Nitrogen being a big *** M'F'er.

Of course, this a band-aid solution to your issue, but one worth exploring if you are at wit-ends on your leaks.

 

Thanks for the info. I took it to the same shop this weekend. They found leaks on the bead again for those two tires. They remounted and applied the bead sealant again. Hopefully this is the end of it. Will check this weekend to see if it loses anything.

 

take the wheels off the rim and submerge in water just so u can find exactly what the problem is, take it from there bro.