There is a lot of information out there about tires. During National Tire Safety Week, I will try to touch on 1 topic per day.
I was on YouTube and found several good videos to help demonstrate tread depth & air pressure. Pirelli has a good one that shows you where to find the proper tire pressure for your vehicle, and how to tell when your tires are almost worn out. https://youtu.be/z-cuWzuZzgc
DO NOT GO BY THE PRESSURE ON THE SIDE OF THE TIRE! That is a maximum setting and it will adversely affect your handling, possibly even causing a blow out. For best performance, follow the vehicle manufacturers tire pressure specifications.
One thing that I try to explain to my customers about tread depth is what it really means.I think that it is really important to understand why there are various grooves and channels in tires. The grooves that go around the tire 360 degrees are designed to help evacuate water. When a tire is new, the tread depth is usually between 8/32" and 10/32" deep. That gives plenty of room to move the water thru the grooves. The smaller blocks of tread aid in traction and will help evacuate water to the sides of the tires. When a tire is worn out, there is not as much room to channel the water. This can cause hydroplaning on wet roads.
I will usually recommend tires be replaced when there is about 4/32" remaining. There is still enough room to move the water and prevent hydroplaning.
Next up.......... Speed ratings on tires