Tire Depth Gauge?

As a former tire salesman, these tools were indispensable. The purpose is to measure the actual depth of the tread on the tire. You put the flange across two adjoining ribs of the tread, and then push the center piece down. Then, you pull the tool back out and read the tread depth. When a tire is at 2/32 of an inch, the wear bars should be showing. At that time, the tire is legally worn out. However, I'd really recommend replacing a tire long before it is that worn for your own safety. BTW, new tires for passenger cars are typically 11/32 of an inch or more, depending on the model. Most tire stores will have a "tire tread depth" chart available on their websites.

TucsonJim wrote:
As a former tire salesman, these tools were indispensable. The purpose is to measure the actual depth of the tread on the tire. You put the flange across two adjoining ribs of the tread, and then push the center piece down. Then, you pull the tool back out and read the tread depth. When a tire is at 2/32 of an inch, the wear bars should be showing. At that time, the tire is legally worn out. However, I'd really recommend replacing a tire long before it is that worn for your own safety. BTW, new tires for passenger cars are typically 11/32 of an inch or more, depending on the model. Most tire stores will have a "tire tread depth" chart available on their websites.

Uh. 2/32 wouldn't that be a sixteenth of an inch?:h

Yes, but the gauges read in 1/32 increments. And the tire shops all talk in 1/32". If you go in and say "my tires are 3/16" instead of 6/32", they'll know you are a novice.

The one I use only costs a penny, and it never wears out.:B

SAR Tracker wrote:
The one I use only costs a penny, and it never wears out.:B

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Unless you're in Canada. Our govt officially mothballed the penny earlier this year. We will have to figure the 2/32 mark on the nickel.

Beverley & Ken

Don't most tire failures come from the sidewalls rather than the tread, anyway? Certainly tread wear affects safe handling but I'll bet the sidewalls fail before the tread becomes thin enough to be a concern.

I was fleet maintenance officer for our dept's cruisers and always carried a tread gauge in my pocket. I was one of the worst to wear out tires as I had a reputation for never getting out of my car while on the job unless something happened. I also used the Lincoln Penny which works just as well. The reason we kept an eye on the tread is because we needed handling at all times and never worried about the sidewalls because the tread wore out long before the sidewalls.

I think (at least some) new RV/LT tires are 12- or 14/32.

mockturtle wrote:
Don't most tire failures come from the sidewalls rather than the tread, anyway? Certainly tread wear affects safe handling but I'll bet the sidewalls fail before the tread becomes thin enough to be a concern.

No. Most tire failures are "Belt leaving Belt Separations" - commonly called a "Tread Separation". Sidewall separations are virtually unheard of.

- BUT -

There are tire failures caused by road hazards - such a punctures - that are frequently mis-diagnosed. The most common is called a "Run Flat", where the tread detaches in the form of a hoop from the sidewalls - and as the name implies, the cause is a tire being operated with little or no inflation pressure. 90% of the time, there is a visible puncture - and the other 10% the damage is disguised in the sidewall damage.

Beverly & Ken,

I will send you an official US tire tread measuring penny for only $19.95 plus $12.50 shipping and handling. But wait there's more!!! Act within the next 30 minutes and I will double your order for just the additional S&H.