Need help buying tires , 55 to 50

[micky]

I usually just buy whatever the used tire store has, but I think he had
trouble finding the size I need last time, so I looked online.

This is for a 2005 Toyotal Solara SLE convertible. The current tire is
215/55R17, as recommended by the maker.

Questions come to mind:

1) I once had 2 directional tires, that had to spin in the right
direction. It was a nuisance. IIRC after I hit a curb and ruined the RF
tire, I had to change 3 tires to get those two to come out right. Can I
count on advertisements for directional tires to say that they are,
especially if I'm ordering online?

I don't see anything like that for any of the tires I've looked at, but
maybe none of them have been one-way only.


2) Then, I find at Firestone:
Tire installation includes
TPMS Reset (not a new kit or sensor)

Doesn't that just mean pushing the button on my dashboard?
Is that really worth itemizing? or are some customers so ignorant
that it seems like it's worth money?


3) Everything else being equal, are quiet tires really quiet, enough to
notice the difference?

An example if you want one:
https://www.firestonecompleteautocare.com/tires/brands/bridgestone/turanzaquiettrack/67?15859838166466

Partly, I use the sound to know how fast I'm going. Will I have to
learn all over again?


4) The tire above is $172, at Firestone or SimpleTire (installation
extra at both places. SimpleTire recommends Firestone and gives the same
price Firestone charges even for tires they sell.)

But this tire, same make and model, almost the same size, is $87
https://simpletire.com/bridgestone-p215-50r17-146974-tires?stmodel=turanza-serenity-plus&stcategory=all-season&sttype=passenger&utm_source=google&utm_medium=cpc&utm_campaign=G_Search_NB_TireModel&utm_content=Profit-Bucket_Passenger_Competitive_HighProfit_RAD&utm_term=&utm_creative=383435609759&gclid=CjwKCAjwvZv0BRA8EiwAD9T2VRrUQkuS-L7_H8vCn7X5_l18D0an_Ns565Sdn4lTE5sk6ZNnf_WwyhoCrA8QAvD_BwE
It's 215/50R-17 instead of 215/55R-17, so iiuc it's 50/55ths of the
diameter, 10/11ths, or 1/11th smaller, so it will have to rotate
11/10ths more times. So 25,000 miles will seem like 27,500 miles to the
bearings and the tire tread. But these are the rear wheels in a FWD
car, and I don't even drive much, so does it really matter? And it's
half the price.

BTW, relevant to question 1, in the simpletire link above, this tire
surely looks like a one-way tire, because the tread is not the same,
neither left to right vs. right to left, nor CW vs. CCW. I guess this
is what makes it a quiet tire, but maybe it makes it a directional tire
too?

TIA

[thekma...@gmail.com]

First question is, why do you want to change tire profile?

Have you experimented with different pressures, or
checking alignment?

[AMuzi]

I have no idea on your questions regarding tires.

Your '50' or '55' is an aspect ratio, not a diameter.
If you knew the actual rollout (loaded circumference at
proper pressure) you could know the difference between them
for rotations per mile or per engine speed etc. But you don't.

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[Scott Dorsey]

micky <NONONOa...@rushpost.com> wrote:
>I usually just buy whatever the used tire store has, but I think he had
>trouble finding the size I need last time, so I looked online.
>
>This is for a 2005 Toyotal Solara SLE convertible. The current tire is
>215/55R17, as recommended by the maker.

1. Go to tirerack.com. They are honest, their prices are good. The
customer reviews are doubtful because they are often made by people who
have just changed from a failed tire to a new tire and are impressed with
the improvement.

2. Tires with directional tread look like they have directional tread. If
you see a V shape or you see a center rib, it's a directional tire. I
like directional tread designs; they perform much better on wet roads.
Yes, they limit your ability to easily rotate tires.

3. TPMS reset on many newer cars requires plugging in an OBD-II tool and
telling the computer there is a new tire. Not a huge deal, but a thing
worth billing for.

4. The difference in noise between different tires is substantial, but
tires sold as "quiet" aren't necessarily quieter. If you drive a very
quiet car where the tire noise is one of the worse noise sources then
you might worry about trying different "quiet" tires. Note that the
customer ratings about noise on tirerack bear no connection with how
noisy the tire is.

--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[dpb]

On 4/4/2020 6:14 AM, micky wrote:

...

...

> It's 215/50R-17 instead of 215/55R-17, so iiuc it's 50/55ths of the
> diameter, 10/11ths, or 1/11th smaller, so it will have to rotate
> 11/10ths more times. So 25,000 miles will seem like 27,500 miles to the
> bearings and the tire tread. But these are the rear wheels in a FWD
> car, and I don't even drive much, so does it really matter? And it's
> half the price.

Aspect ratio gives profile and is ratio of sidewall section height to
section width...but the overall diameter is

Doverall = Drim + 2*Hsection

So the ratio of the two tires is

(Drim + 2*Hsection)/(Drim + 2*Hsection*55/50)

Well, this is simple w/ MATLAB which is open in other window...

>> fnHSect=@(SW,AR) SW*AR/25.4/100; % Section Ht inches
>> fnHSect(225,55)
ans =
4.87
>> fnHSect(225,50)
ans =
4.43
>> fnD=@(Drim,SW,AR) Drim+2*fnHSect(SW,AR) % Overall diameter (in)
>> fnD(17,225,55)
ans =
26.74
>> fnD(17,225,50)
ans =
25.86
>> fnDrim(17,225,55)/fnDrim(17,225,50)
ans =
1.0343
>>

So there's only roughly a 3% difference in overall diameter instead of
10% because the rim diameter is the bulk of the overall dimension, not
just the section height.

All in all, it doesn't matter enough that you'll notice it other than,
perhaps, the lower profile will drive and ride a little more stiffly.
Whether you'll actually notice unless you drive the vehicle very hard is
doubtful.

Why there's so much difference in price I've not looked at at all...more
marketing than anything else one would suspect.

Nice drawing/explanation at
<https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=7>

--

[thekma...@gmail.com]

Scott Dorsey:
RE: Tire Noise vs Ratings

By stating that "customer ratings on Tire Rack have no bearing on
actual tire noise", are you suggesting that how noisy a particular tire
is is subjective?

[dpb]

On 4/4/2020 9:30 AM, dpb wrote:
...

> Well, this is simple w/ MATLAB which is open in other window...
>
> >> fnHSect=@(SW,AR) SW*AR/25.4/100;     % Section Ht inches
> >> fnHSect(225,55)
> ans =
>           4.87
> >> fnHSect(225,50)
> ans =
>           4.43
> >> fnD=@(Drim,SW,AR) Drim+2*fnHSect(SW,AR)  % Overall diameter (in)
> >> fnD(17,225,55)
> ans =
>          26.74
> >> fnD(17,225,50)
> ans =
>          25.86
> >> fnDrim(17,225,55)/fnDrim(17,225,50)
> ans =
>     1.0343
> >>

...

Sorry, missed a fixup on renaming the overall diameter anonymous
function...in last section...

> >> fnD(17,225,55)/fnD(17,225,50)
> ans =
> 1.0343
> >>

--

[dpb]

On 4/4/2020 9:30 AM, dpb wrote:
...

> >> fnDrim(17,225,55)/fnDrim(17,225,50)
> ans =
>     1.0343
> >>
>
> So there's only roughly a 3% difference in overall diameter instead of
> 10% because the rim diameter is the bulk of the overall dimension, not
> just the section height.

...

Just noticed was 215, not 225. Minimal difference but for the record...

>> fnD(17,215,55)/fnD(17,215,50)
ans =
1.0332
>>

--

[Scott Dorsey]

In article <a0989f09-973d-43f8...@googlegroups.com>,

No, one could measure it objectively. But the people who write reviews
on Tire Rack do not. They just replaced their bald Comfortreads with
brand new Defenders and... wow... they handle so much better and don't
make that swishing noise!

Most of the people making comparisons are comparing bad worn-out tires
to new tires, and this is not a fair comparison.

[thekma...@gmail.com]

Scott Dorsey:

Your 'swishing' comment triggered something I remember from
decades ago, but rarely ever hear anymore:

Back in the '70s, the tires on about one out of every five cars going by a
busy street made a crackly gravelly sound. Like it had a hundred pair of
casino dice inside the tires or something. I forgot what someone said that
was.

Do you remember that?

[Jim Joyce]

Of course, but it helps you to calculate the nominal diameter. The formula
is simple:

rim diameter + ((tire width * aspect ratio as a percentage) *2)

Converting the 17" rim diameter to mm, you get 431.8
((215 * .50) * 2) = 215
215 + 431.8 = 646.8

((215 * .55)) * 2 = 236.5
236.5 + 431.8 = 668.3

Now you can compare 646.8 to 668.3.

All of those are nominal values. Production differences will cause some
variation, not to mention wear as a tire is used.

[Arlen Holder]

In response to what Scott Dorsey <klu...@panix.com> wrote :

> one could measure it objectively. But the people who write reviews
> on Tire Rack do not. They just replaced their bald Comfortreads with
> brand new Defenders and... wow... they handle so much better and don't
> make that swishing noise!

While I find it's literally both trivial & impossible to properly select
tires by its known trusted specs, I do well agree with others on the almost
total lack of validity of most "boy racer" tire reviews on the net.

As for objective measurement...
o Measuring and Reporting Tire-Pavement Noise Using On-Board Sound Intensity (OBSI)
<https://docplayer.net/26626443-Measuring-and-reporting-tire-pavement-noise-using-on-board-sound-intensity-obsi.html>

They essentially mount a probe at the x:y:z 3-dimensional leading &
trailing edges of the tire contact patch with the road surface at 60mph:
o 4 inches horizontal from the tire sidewall
o 3 inches vertical above the pavement
o 4.125 inches in front and behind the axle centerline

Typical concrete tire interfaces, they say, generate from 99dBA to 108dBA
reported in the 400 Hz to 5,000 Hz band, where (get this), the results are
viewed in Google Earth!
--
Usenet works best when adults post with purposefully helpful intentions.

[Arlen Holder]

In response to what <thekma...@gmail.com> wrote :

> I forgot what someone said that was.

I don't know what _that_ noise was, but this tire-seller page (so take it
for what it's worth), "claims" tire noise can be from a variety of
causes...
o How to Keep Tire Noise Down
<https://www.discounttiredirect.com/learn/tire-noise>

1. UNBALANCED TIRES
2. TIRES THAT NEED ROTATING
3. OFF-ROAD AND PERFORMANCE TIRES
4. UNEVEN TREADWEAR
5. UNEVEN OR LOW TIRE PRESSURE
6. DEBRIS IN TIRES

The cynical may note that the tire seller in question holds most of the
solutions, or so it might seem...

This article at least explains somewhat that tire noise is normal...
o Common Causes of Tire Noise and How to Fix Them
<https://www.liveabout.com/tire-noise-3234473>

"Wide tires generate more noise than narrow tires..."
"Touring tires and low-rolling-resistance (LRR) tires are typically
the quietest, while snow tires and off-road tires are the noisiest
(studded snow tires are even louder). Performance tires and all-season
tires fall somewhere in between. Because of their stiff sidewalls,
run-flat tires (RFT) are usually noisier than non-RFT tires."

"Low-profile tires typically generate more noise because there is less
rubber sidewall to absorb it. This noise gets transmitted through the
chassis and the rest of the vehicle. While these tires offer improved
traction, they can sometimes generate excessive noise."

For what it's worth, Consumers Union does test & report for measured noise.
o Consumer Report: Tire Rating & Reviews
<https://www.consumerreports.org/products/tires/ratings/?type=performance-all-season-tire>
--
Usenet is so much more valuable, and pleasant, when people share solutions.

[micky]

I'll get back to you about individual replies but I see a tire store
here advertising rim seals for $15/tire but I can't find anything about
them with google.

They're closed now but do you know what rim seals are.



In alt.home.repair, on Sat, 04 Apr 2020 07:14:06 -0400, micky