When do you change your tires?

[Paolino]

Okay...

So, the funny thing is, every car I've ever owned I've never had to really buy new tires because the car has always died before I've needed new ones. Now, with my current car, I've had it a while, and I bought new tires when I first got it because my mechanic recommended it before I actually purchased it, but now I'm wondering if I need new ones.

Exactly how bad do you let tires get before you change them?

I have tread on them.. it's not like they're bald. However, yesterday I skid for the first time since I've owned the car since April 2002. Now, I'm thinking it was simply because of the road...

... it rained lightly yesterday and I was on my way to the other building, when I came to a turn. As I approached, I noticed the road looked like a future homosexual GM color name: Rainbow Tar Metallic... the road had that rainbowish color on it, probably from the oils accumulating at that spot. I kinda let a little "Oh $h!" out because I needed to stop and it looked bad, and I pumped my brakes, but it was really a close call... I did stick out a little into the oncoming traffic (flying past me at about 60). When the light turned green, I skid as I gently applied the gas.

So, again, when do you know when to replace them? It's been a very mild winter here, so there have only been a few icy mornings and I haven't had any problems. I rotated my tires a few months ago, and I was going to consider replacing them in the summer, but maybe I shouldn't wait so long.

What's the rule?

[pow]

I replace 'em whenever it reaches the wear indicator bar, but then again, it never really rains here. A recent study suggests replacing them earlier.

[Drew Dowdell]

Take a penny.

Stick the penny in the tread so that Abe Lincoln is going in head first.

If you can still see the top of Abe's head by the time the penny stops, you need new tires.

Tread should be about even depth across the surface of the tires. If there is a variation, you either have an inflation/deflation issue, alignment issue, or some other suspension issue. Any issues <except those caused by air pressure> should be taken care of before, or at the same time as the tire change out.

Edited January 6, 2007 by Oldsmoboi

[loki]

supposedly if you turn a penny upside down and you can see abe's whole head, new ones are needed,

or if the wear bars are as high as the tread.....

[Paolino]

I replace 'em whenever it reaches the wear indicator bar, but then again, it never really rains here. A recent study suggests replacing them earlier.

What's the wear indicator bar look like?

I'll take a penny to them tomorrow. They're worn pretty evenly... I had an alignment done as well, when the tires were rotated.

[pow]

They go across the tire...

When the tread is level with the bar, it's definitely time to replace them.

[balthazar]

I run tires down to the wear indicator, or I will replace them if for whatever combination of reasons, they spin/skid too often in normal circumstances.

Ironic subject matter: I just rotated my tires this afternoon- fun job without a lift.

[Nick]

Tread should be about even depth across the surface of the tires. If there is a variation, you either have an inflation/deflation issue, alignment issue, or some other suspension issue. Any issues <except those caused by air pressure> should be taken care of before, or at the same time as the tire change out.

Sometimes the manufacturer dials in stock negative camber...like in my car, it comes with about 2.2 degrees of negative camber. (In fact, I believe most, if not all BMW's are like that). It eats the rear tires fast though, so my tires don't last too long. My Michelin PS2's I am lucky to get 20k out of, if even that. So I'm replacing tires at least once a year. When I upgraded my suspension and had the 4 wheel alignment done they tones down the rear camber to about 1.97 so spare my tires a bit.

Usually when my tires start to wear out it is a little too late...It is sometimes hard to spot early. I've worn them completely flat before, but often times the inside of the rear tires will start to show cord first.

[trinacriabob]

Take a penny.

Stick the penny in the tread so that Abe Lincoln is going in head first.

If you can still see the top of Abe's head by the time the penny stops, you need new tires.

They measure tread depths in 32nds of an inch. I believe most tires start with 10/32". The "head of the Lincoln penny" test should put you at 2/32". At that point, the tire wear bars (transverse to tread) should be even with the treads. In the wetter East, that would be getting risky. Of course, poor alignment (bashing curbs and such) will cause the tread to wear sooner and unevenly, meaning you will not get the maximum life out of the tires. Worn struts will also take an additional toll on your tires, thus shortening their useful life.

I believe they have Costco on "the Island" or some facsimile thereof. When you do get new tires at a place like that, they will rotate them for FREE. I take them in for rotations every 5K to 6K and have gotten the estimated tread life out of my tires.

Also, as soon as you get tires:

(1) get the alignment done and watch the ruts/curbs from then on, and

(2) check how your struts are doing (it's easy to test them via the "bounce test")

Costco, unfortunately, neither aligns nor sells suspension components.

When you do go in for rotations, ask them for treadwear readings. They have this little prong that fits in their "pocket protector" and they can give you all the readings in about 2 minutes, that way you can see that you are working your way down from 10/32" in a "proportionate" manner...or at least, you should be.

[Cory Wolfe]

I replace 'em whenever it reaches the wear indicator bar, but then again, it never really rains here. A recent study suggests replacing them earlier.

That's basically what I've been told. Ironically, it reached the indicator during the fall. Oops.