In theory a tire without puncture, good valve stem, well mounted should not leak any air in a short period of time (i.e. 6 months). This is the case if you have a new car. I remember when my car was new, I only checked the pressure every few months and the pressure is good, no loss. Occationally, I get a few pounds less across all tires, but I guess that was because I haven't checked for too long, like a year. Then I replaced my tires without putting in new valve stems. Big mistake! I had to put some air in every now and then... 
So, make sure you get a new valve when you buy new tires! |