Tire Treadwear number, what does it mean
ear...@po-box.mcgill.ca
what does that treadwear number on the side of the tire mean?
Mine say treadwear 160 on my potenza RE92
on my friends all season shit tires, they say 400
is the lower the treadwear number, the more it will wear out?
what does it all mean?
thanks
dbug
AS I recall, the govm'nt did some test a few years ago and determined
that the test tire would go 20k miles before it wore down to 2/32
tread. A tire that would be expected to duplicate that mileage was
assigned a tread wear rating of 100. Thus, a tire rated at 100 should
last about 20k miles. A tire rated at 400 should last 80k miles if
tested under the same conditions. Your mileage may vary.
Marcel Bourque
more wear and smaller ones will wera out faster. I wonder what size
tire they use for testing???
For example, a 195/60R14 Goodyear Eagle GA has a treadwear of 320.
You will get a lot less wear out of those than from a larger size
Goodyear Eagle GA which will have a 320 treadwear also.
You're right also, milage will vary depending where you drive and how
you drive. Tires wear out faster in warm weather as the rubber gets
softer, etc......
*****************
Marcel Bourque
New Brunswick, Canada
98 Dakota CCab SLT 4x4
Remove "NADA" from address to e-mail me
No-Spam
> what does that treadwear number on the side of the tire mean?
> Mine say treadwear 160 on my potenza RE92
> on my friends all season shit tires, they say 400
Higher treadwear number doesn't mean that the tire is shit, it just means
it's a harder compound and will last longer. Some high treadwear tires
actually perform quite good.
Anyway, a treadwear of 160 is similar to the one on our Pzero, this mean it
will melt off your rim in about 18-22,000 miles :-) Assuming that you keep
them properly inflated all the time and that your alignment is true.
If you want to save bucks, you can either but a new set of rims with more
durable tires for everyday use and use the soft stuff for weekend tours.
Or just buy VR rated tires if you never ever drive in the speed range
backed by the ZR rating.
dbug
Part of the assumption was that a larger tire would also carry a
proportionately higher load which would make the rating stay pretty
close - i.ei a large car would require a larger tire that would be
expected to be heavier. there wasn't a distinction made because of
that. But, if you use a larger tire than that required by the
manufacturer and, of the same tread wear rating, you should beable to
get more miles from them.
Vicente Munne
<snip>
>is the lower the treadwear number, the more it will wear out?
>what does it all mean?
>
>thanks
As others has pointed out a 320 tire should last twice as much as
your 160 tire everything else being equal but I should point out to you that
this is not a required government test for tires but a test that manufacturers
perform themselves. That means that for the same manufacturer a 400 tire
should last twice as much as a 200 tire but two 200 tires from different manu-
facturers do not necessarily last the same.
Cheers
--
VICENTE MUNNE
Materials Science and Engineering Department
Georgia Institute of Technology, Atlanta Georgia, 30332
Internet: gt9...@prism.gatech.edu
Stephen H. Westin
> On Wed, 30 Sep 1998 01:37:36 GMT, NADA...@NADAnbnet.nb.ca (Marcel
> Bourque) wrote:
>
> >Depends on the tire size also. A larger diameter tire will get a lot
> >more wear and smaller ones will wera out faster. I wonder what size
> >tire they use for testing???
> >
> >For example, a 195/60R14 Goodyear Eagle GA has a treadwear of 320.
> >You will get a lot less wear out of those than from a larger size
> >Goodyear Eagle GA which will have a 320 treadwear also.
> >
> >You're right also, milage will vary depending where you drive and how
> >you drive. Tires wear out faster in warm weather as the rubber gets
> >softer, etc......
Just cruise DejaNews for the 9/16 article from jdixon (The Auto
Expert). It explains the rating process in painful detail.
Here's just a bit:
"Treadwear grades are developed first by running the tires being
graded, called ``candidate tires,'' over a selected 400-mile segment of
public highway near San Angelo, Texas. After an 800-mile ``break-in''
run, the candidate tires are driven over the test course for a total of
6,400 miles in test convoys composed of 4 passenger cars and/or light
truck vehicles.
and
Special tires known as ``course monitoring tires'' (CMT) are used
as the control in grading candidate tires. CMTs are specially designed
and built to American Society for Testing and Materials (ASTM) standard
E1136 to have particularly narrow limits of variability.
and finally,
Once the BCWR for the new CMTs was established, these CMTs were
used to grade candidate tires. Upon completion of the 6,400-mile test,
the BCWR was divided by the average wear rate of the CMTs to determine
the CSAF for the candidate tires. That factor was then applied to the
wear rates of the candidate tires to obtain the AWR of the candidate
tires. That AWR was then extrapolated to the point of wearout
(considered to be 1/16th inch of remaining tread depth). The
resultant value was then converted to the treadwear rating of the tire."
In summary:
o NHTSA does the testing, not the manufacturer
o All tires of a given size are compared against the *same* standard
o There's extrapolation involved, so beware
One of the artifacts of this test is that certain "street legal"
racing tires (like BFGoodrich drag tires) actually get a rating of
zero, since they start with extremely shallow tread that wears down to
1/16th or less in the 800-mile break-in period.
--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.