S02 pole/es100

[Mrdi]

Well the Bridgestone S02 rear poles are about ready to replace.

Could I put on the rear Yoko avs es100 since the s02 is not made anymore? would be nice to have the 245 50 instead of the 245 45 which makes the odometer off by 15%
Thanks,

Mrdi2003@yahoo.com

[speeder]

Are you sure that the SO2s can't be gotten? Seems that they were still listed on www.tirerack.com not too long ago, but maybe not anymore.

Not sure that you would want to mix es100s w/ SO2s on front, (that's what you meant, right?), different characteristics/performance front and rear. I found the reviews and tests/comparisons on tire rack site really helpful, even if you do not plan on buying there.

And 245/45s really throw the odo off that much? Would not have thought so, but I'll listen to your experience. Guess that's what they mean by "YMMV".

[89911]

If you are interested, I may be selling a set of 225/50/16 S03's. I mounted these on a 8 by 16 front wheel and it is interfering. I switched to a 225/45/16. They have about 2 miles on them from a test drive at the shop. Hence the reason I may not be able to return them. Let me know, I'll give you a good price.

[jmohn]

BTW, difference between a 225x50/16 (standard wheel/tire) and a 245x45/16 is closer to 1% not 15%.

Jerry M
'78 SC

[89911]

Originally posted by jmohn
BTW, difference between a 225x50/16 (standard wheel/tire) and a 245x45/16 is closer to 1% not 15%.

Jerry M
'78 SC

There is exactly 1" shorter diameter, 23.9 compared to 24.9.

[Wil Ferch]

Somebody's math is wrong: ..

225/50-16
225 is 8.85"
8.85 x 50%= 4.429
16 + 4.429 + 4.429= about 24.85" diameter

245/45-16
245 is 9.64"
9.64 x 0.45= 4.34
16+ 4.34+ 4.34 = about 24.7" diameter.

About the same...

Wil Ferch

[Embs]

Tire Height Calculating Form


http://www.procomptires.com/tireconversionchart.html

[Wil Ferch]

oops:

Me bad...i'm looking at the latest posts instead of the first one.....

245/50-16 = 25.64", using the same math basis...

--Wil Ferch

[Wil Ferch]

89911:
I run S02's and my rears are toast.
Sorry to hijack this thread, but I'm in need of 225/50-16 S02's ( preferably used and scrubbed)...and wonder if S03's can be used as substitutes. If so, I might be interested in your tires,
WFerch911@aol.com

--Wil Ferch

[jmohn]

I still don't see how there can be a 15% speedometer error. The following diameters and circumferences are "nominal", as there are differences between manufacturers.

Assuming "standard tire" is 225x50/16:

225x50/16=24.9" dia., 78.1" circum., 811 rev. per mile

245x45/16=24.7" dia., 77.5" circum., 817 rev. per mile
-0.7% difference (speedometer would read .7% percent fast)

245x50/16=25.6 dia., 80.6 circum., 786 rev. per mile
+3.2% difference (speedometer would read 3.2% slow)

It would seem 245x45 is a better match to the "standard" than a 245x50, but there certainly isn't any 15% difference. Or am I overlooking something?

Jerry M

[89911]

I don't know if all tires fall under this precise measurement. The guy at the TireRack just read me the dimensions for S03's from the manufacturer. As we all know, actual tire dimensions vary widely.

[Wil Ferch]

He read you the wrong size....certainly there are differences but not to that extent. The math we do here usually gets you pretty close.
---Wil Ferch

[Mrdi]

The dimensions are available to you on the TR site.
The revs per mi are the most indicative.
I agree with the theoretical math.
The fact remains.
In a measured three miles the SO3's are 15% fast on the odometer.
Noted CA speedo expert has indicated there are no adjustments just gear changes and....
he has had many complaints about the SO3's in this realm.
That the specs are misleading.
My odo confirms his perception.
I have more faith in the odo than I do in a salesman, skeptic that I am.

[Mrdi]

J Mohn,
Here are the SO3 specs from tire rack:
Note the revs for the 245 45 16 SO3.
847 not 811
Therin is the problem
Thank you MR salesman
Caveat emptor!!
Revs per mile the last number under each tire shown 245x45x16 = 847 revs per mile ALOT!!

225/55WR16 95W SL
220 AA A
1521lbs.
51psi
10/32nds
6-8"
7"
9.2"
8.3"
25.7"
811
245/45YR16 94Y SL
220 AA A
1477lbs.
51psi
10/32nds
7.5-9"
8"
9.6"
9.1"
24.6"
847

[KTL]

Mrdi,

First you ask about 245/50 vs. 245/45.

Now you post specs for a 225/55 vs. 245/45................ I don't follow.

I assume you're running a 245/45 right now? The S-02 is not offered in that size.

All of the 225/50 (standard factory rear size) tires for brands you mention have revs/mile:

ES100: 829
S-02 (N3 Porsche): 843
S-03: 837

All of the 245/45 tires for brands you mention have revs/mile:

ES100: 843
S-02 (N3 Porsche): N/A
S-03: 847

All of the 225/55 tires for brands you mention have revs/mile:

ES100: 805
S-02 (N3 Porsche): N/A
S-03: 811

Please explain???????

[jmohn]

Originally posted by Mrdi
J Mohn,
Here are the SO3 specs from tire rack:
Note the revs for the 245 45 16 SO3.
847 not 811
Therin is the problem
Thank you MR salesman
Caveat emptor!!
Revs per mile the last number under each tire shown 245x45x16 = 847 revs per mile ALOT!!
847

Actually, I said 817 rev. per mile for a 245x45/16, but I didn't go to "Tirerack" for it, I just did the math based on an "average" 245x45 diameter of 24.7" (BTW, Tirerack's own math is wrong, if the dia. of a 245x45/16 S03 is 24.6 then the rev. per mile should be 820.3 NOT 847). Regardless of any of the above anomalies, the difference still isn't 15%, which was my original point. S03's may indeed cause speedometers to read erroneously, but now I've lost interest.

Jerry M

[Mrdi]

Must be cold in Minnesota!
Cheers
Mrdi

[jmohn]

Hey, Mrdi:

It's getting better, but winter seems to get longer every year. Last weekend I went out in the garage just to sit in the SC (and watched my breath fog up the windows). Maybe in the 50's this weekend, warm enough to change the plugs.

Jerry M
'78 SC

[KTL]

Forgive me, but this breakdown seems to happen too often when Mrdi posts a topic.

Maybe if you'd be more specific about the purpose of your topic (read: take some time to make your post clearly understandable as to what is your question) then you might get some positive feedback about the issue.

Also, you rag on jmohn after he points out the error in Tire Rack's tire diameter vs. revs per mile calculation???? Nice. Good way to get some help with your dillemma.

[Mrdi]

Have to change your plugs, around here, inside today or you'd get sunburned. Ouch!
78 Far. Wind WSW @ 3KTS. swell running 4-5 ft.
But..... the water temp is 58.