Tire Tread Depth - what do these numbers mean? - answered. Thanks!

SwiftWind

Platinum Member
Sep 27, 2004
2,583
20
91
I had an oil change done on my car along with checking other fluids and the tires as well. My tire tread depth numbers were ranging from 7/32 to 9/32. Are these good numbers? What are bad numbers? how do they measure these?

I always changed tires just by looking at them really and seeing if there's about a cm or so left.

Thanks for your time.

EDIT: Got the answers. thanks!!
 

Engineer

Elite Member
Oct 9, 1999
39,234
701
126
All tires (that I know of) have tread wear indicators located on them. There is a bump between the treads that indicates when a tire should "probably" be changed. If the bump is "even" with the tread, then it's time - but many people feel that it's OK to keep on going!

7/32 to 9/32 is around 1/4" so I would think that would be great treadlife left.

Drive em till they are slick! ;) (j/k)
 

scorpmatt

Diamond Member
Feb 8, 2001
7,040
96
91
have no clue what those numbers mean.

here's my two cents: take a penny, stick the penny upside down so lincoln's head is going into the tire. if the tread doesn't meat or go above his head, the tread's beyond the legal limit, time to change it
 

dethman

Lifer
Oct 12, 1999
10,264
3
76
new tires typically have 10/32 tread. you have to replace them at 2/32 or 3/32. so your tread is fine.
 

tfinch2

Lifer
Feb 3, 2004
22,114
1
0
Stick a penny in the tread upside down. If the tread is higher than Lincoln's head you're fine.
 

OrganizedChaos

Diamond Member
Apr 21, 2002
4,525
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you can use a computer but can't read a fraction?

edit: anyway just do what engineer said, replace them when they get down to the wear bars unless you need them for mud or snow.
 

clickynext

Platinum Member
Dec 24, 2004
2,583
0
0
Originally posted by: tfinch2
Stick a penny in the tread upside down. If the tread is higher than Lincoln's head you're fine.

What if you're Canadian, and all you have on your penny is the queen?
 

skimple

Golden Member
Feb 4, 2005
1,295
3
81
Originally posted by: clickynext
Originally posted by: tfinch2
Stick a penny in the tread upside down. If the tread is higher than Lincoln's head you're fine.

What if you're Canadian, and all you have on your penny is the queen?

Use a loonie! If the tread is higher than the duck's @ss, you're OK.
 

eelw

Diamond Member
Dec 4, 1999
9,026
4,340
136
Originally posted by: clickynext
Originally posted by: tfinch2
Stick a penny in the tread upside down. If the tread is higher than Lincoln's head you're fine.

What if you're Canadian, and all you have on your penny is the queen?

It's the same. If you can't see Queen Elizabeth's crown, you're okay.