[burly]

A 2-3psi loss in tire pressure over a month or so's time is common. I recommend that you get a tire gauge and keep it in the car. Then when you get gas and while its pumping, just check the tires. If they are low, then add a little while your there. This has two major benefits - 1. The gauges on the air machines are often not correct and vary from machine to machine. By checking with the same gauge each and every time, you have an established baseline and aren't thinking your low when its just a different machine, etc. 2. By keeping your tires properly inflated, they wear evenly, last longer and yield optimal fuel efficiency. As for the squeak over large bumps, unless its unusually loud - loud than in the past - its probably normal. If its noticably louder or different than what it has been in the past, it would be worth further investigation.