Is that thing about tire wear and penny still true

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Dealer told me it's time to change tires. 3/32. Top of Lincoln's head goes below groove.

These are stock all season radial Hankooks.

Is the penny thing still true? Was it ever true?
 
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I go by the wear bars between the treads which is 2/32 unless I'm heading into the rainy season then I change at 3/32. I think the penny measurement was used before the wear bars were mandated and molded into all auto tires. Ed
 
you are probably ok for a few months if there is no rain.

if rain.. then yes you need new tires asap.

2/32 is legal.
 
The penny dimensions haven't changed, Lincoln's head is still the same size and position, and the legal definition of worn is still 2/32, so it is still true
smile.gif


You can probably wait a week or two for the Memorial day sales, which would be the best time to get tires.
 
Originally Posted By: MinamiKotaro
Oh, TIRE wear. The title was very confusing.

Dat fo' sho'. At first I thought the thread had to do with the latest fashions for firemen.

They'd better not ever replace old Abe on the penny. Diligent tire-checkers would be lost forever.
 
Originally Posted By: jimbrewer
Dealer told me it's time to change tires. 3/32. Top of Lincoln's head goes below groove.

These are stock all season radial Hankooks.

Is the penny thing still true? Was it ever true?


You WANT the top of Lincoln's head to be in the groove...it's when his head doesn't go in the groove that your tires' tread depth is insufficient.*




* That said, use your best judgement in replacing tires.
 
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You can buy a tread depth tool for under 5$, ive found mine handy to check the tires and when doing tire changeovers in fall and spring.
 
If you need tires I am sure DTD will have a Memorial Day sale. While the Lincoln's head as a tire gauge works it should be only used by college kids who have no money. For those of us who can afford tires, replace them a little sooner. Remember the safest mile on your tires is the first mile and the most dangerous is the last mile. Pushing the tire life to the very end will not save much when viewed as tire cost per mile driven.
 
Long time ago I looked for data on tyre performance related to tread.

There was very little, and mostly negative. IOW there was little or no consistent effect of tread depth on stopping distance. Stopping distance isn't of course, the whole story, but its relatively easy to measure.

In the dry (most of the time here) bald tyres actually worked better, which isn't all that surprising.

So a penny would be fine for me, if I had one.
 
In dry New Mexico, with summer months (no snow) ahead, I would run them until they failed the yearly inspection. At 3/32, you are still very legal.

No one seems to realize that worn tires actually INCREASE traction in dry conditions. I like TireRack and the other vendors too, but keep in mind their agenda is to sell you new tires.
 
Originally Posted By: Miller88
I've never really been concerned with dry performance. Wet performance, yes

Same here, I guess if it was never wet then I've run my mediocre all seasons longer, but they all became a hazard in the rain.
We used run old tires for autocross down to the cords and often you could see the difference in rubber compounds when you got through the traction layer. I've never run a tire on the street down that far though.
 
Wasn't sure I believed myself so I did a quick search. Most of the easily findable stuff is for wet roads, and I couldn't find the original (NZ and Australia, IIRC) research papers.

http://www.tirerack.com/tires/tests/testDisplay.jsp?&ttid=91

Legal minimum tyres handle better, and brake slightly better than new and part worns in dry conditions.

(They suggest a quarter is a better tread gauge than a penny.)

http://www.ectri.org/YRS11/Documents/Final website/Session 1/YRS11_Session1_RajamakiVTT.pdf

80% of accidents in Finland occur in the dry. (It'll probably be a lot more here, or, say, Arizona, or the OP's New Mexico), and there is an association between low tread depth and other illegal or unsafe driver behaviour, which will affect any association between low tread and accidents.

http://www.theday.com/article/20160430/BIZ09/160439995

"Conversely, shallower tread can actually improve vehicle handling in dry conditions. Consumer Reports says the lower tread depth puts more of the tire in contact with the road, improving cornering as well as braking. This quality makes tread-free tires ideal for professional car racing, but not for everyday driving where you're sure to encounter wet or snowy conditions at some point."

- No I'm not. And optimising performance for the "local norm" seems likely to be statistically safer.
 
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Originally Posted By: gfh77665
In dry New Mexico, with summer months (no snow) ahead, I would run them until they failed the yearly inspection. At 3/32, you are still very legal.

No one seems to realize that worn tires actually INCREASE traction in dry conditions. I like TireRack and the other vendors too, but keep in mind their agenda is to sell you new tires.


Unfair. See my link above, where they acknowledge dry performance edge.
 
Originally Posted By: Miller88
I've never really been concerned with dry performance. Wet performance, yes


So you don't mind having a dry accident as long as you don't have a wet accident?

Maybe a potty training thing?
 
Originally Posted By: Ducked
Originally Posted By: Miller88
I've never really been concerned with dry performance. Wet performance, yes


So you don't mind having a dry accident as long as you don't have a wet accident?

Maybe a potty training thing?


but dry accidents are from many things not tires

there is no chart for dry vs wet accidents caused solely by tires.

You prepare for the worst conditions not the best,
 
Shockingly, up here in snowy Ontario, 1.5mm of tread depth is permissible.

That's actually a little bit less than 2/32. Very stupid if you ask me.

2/32 is [censored] in the wet, and I'd be surprised if the vehicle would even move in snow with those 'slicks.'
 
Originally Posted By: Ducked
Long time ago I looked for data on tyre performance related to tread.

There was very little, and mostly negative. IOW there was little or no consistent effect of tread depth on stopping distance. Stopping distance isn't of course, the whole story, but its relatively easy to measure.

In the dry (most of the time here) bald tyres actually worked better, which isn't all that surprising.

So a penny would be fine for me, if I had one.


Well...a long time ago was...a long time ago.

Please read through the Tire Rack links that I provided. Testing shows, conclusively, that decreased tread depth has a significant impact on wet and snow traction.

Snow may not be a problem where you live, but rain certainly is, and a tread depth below 4/32" will reduce your wet traction.
 
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