3 of my summers held 38 psi over the winter, the 4th was around 10 psi
Take a little spit and put it over the valve stem...if it bubbles, its the core.
You can pick up tire fix kit at walmart or most parts stores.
Make sure it has new valve cores, and a core removal tool. Takes five minutes at the most to change, but make sure you are where you can put air in your tire.
Great for off roading and or beach driving when you have to air down your tires quick.



