In his May 2016 inspection report, the YourMechanic mechanic states that all 4 of my tires are in excellent condition. The tread on all 4 is obviously great BUT all 4 tires are just not holding air for longer than a couple days! I admit the tires are old, but I don't drive more than 50-100 miles in a year and my car is stored in a garage. There are no obvious signs of puncture, cracks, etc. So what's going on with these tires?
My car has 48000 miles.
My car has an automatic transmission.
Hi There, There could be a couple of things happening with your tires. Depending on the weather where you live, the tires may lose air pressure even just due to sitting for long periods of time due to the cold, even when stored inside a garage. Air density changes as the temperature drops causing pressure to also drop. Since the tires get very little use, this means they are subjected to very little activity that would otherwise generate heat and maintain the air density necessary to maintain pressure. The other possibility may be that you may have valve stems that may have slow and small leaks in them. When you put air in the tires using that small valve on the tire, there is a small spring inside this valve that is depressed to allow the air to be pumped into the tire. Over time, these springs can lose strength releasing small amounts amounts of air over time. Another way to help prevent this type of fluctuation in tire pressure is by the use of Nitrogen in your tires rather than regular air. As you may know, air is approximately 78% Nitrogen, 21% Oxygen and the rest is water vapor and some other small concentrations of gases. Nitrogen is much less likely to migrate through tire rubber than oxygen. This will maintain your tire pressure much more consistently during large temperature fluctuations. You may want to consider having your tires checked for leaks at a local tire shop to determine what may be causing this.
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