Tires: When to really change tires?

Question
Hi Barry,

I just took my 2011 Camry in for maintenance which has 45k miles. I was told everything was good except they marked all my tires as red requiring urgent attention and said I needed 4 new tires and wanted to charge me about $800. Here are my questions:

1. When do I REALLY need to change my tires? The tires look completely fine to me, I know there is some wear on them, but I have certainly seen much worse on other cars getting along fine. What happens if I don't change my tires? I of course will change them if they are completely worn out, but they don't look that bad to me.

2. Is there a recommended time line on when I should be getting new tires? After a certain amount of years or miles?

3. How much should tires cost? Where is the best place to get them and have them installed?

4. Finally, I was told that my tires were rotated. What exactly does that mean? One of the tires has a missing hubcap and it is in the same spot, are they supposed to move front tires to back? Left to right? What does this service actually do and how do I know if it was actually done?

Sorry for such basic questions, I don't know anything about cars. Thanks very much for your expertise.

Answer
Kyle,

There is an increasing risk of wet and snow traction problems as tires wear.  The problem is that there is no break point at which beyond that point things suddenly change.  It's gradual.

Current thinking says that if you live in an area with snow, you should replace your tires when they reach 5/32nds of an inch tread depth remaining.  If snow is NOT in your area, then 4/32nds.

Remember, it isn't the day to day traction that causes issues.  It's those bad weather days that are the ones you have to worry about.

Time?  There have been a number of statements made and my take is that if you live in AZ, CA, NV, TX, and FL, you should replace your tires every 6 years.  If you live in MN, WI, MT, ID, and ND, it's 10 years.  States in between are .... ah ...... in between.

But an inspection may reveal the tires are aging faster than what I just wrote - generally due to adverse condition - and cracking is the evidence.

How much should tires cost?  Sorry, that is highly dependent on what tires your vehicle needs.  Some take very expensive tires, and some take very inexpensive tires.  Plus, there are differences between brands - with highly reputable brands costing more than less reputable ones.

Rotating tires is moving the tires and wheels to a different position on the vehicle in order to even out wear. This should be done every 5 to 8 thousand miles.

There are a lot of different rotation patterns but the basic pattern is front to rear.  The fact that one wheel still has a missing hub cap is probably because the hib caps were taken off to do the rotation and the hub caps were put back on in the same position.

The way to tell if the tires were rotated is to see if there is some other sort of evidence - like tire wear, or brake dust differences.