I had a tire that was leaking slowly, I checked it twice and they kept telling me everything was fine. I drove it for about 6 months and filled it up every now and then when the tire pressure light came on. Towards the end I had to fill it out once a week, luckily I had it and it was sooooo easy. When I brought it back for inspection they told me I had a nail in the inner tread so I needed a new tire. I was so thankful that I had this car. I would spend a small fortune to buy air at gas stations. It's worth it! Just set the tire pressure and it will stop once it reaches that pressure.