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Tire Size

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Michael Oritt

Michael Oritt

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I need to replace my tires--I'm currently running Michelin 175/70 ZX's which are no longer being made by Coker. Alan Hendrix of Hendrix Wire Wheels tells me that he has sold a few sets of a Gillett Wide Track brand (made by Firestone) tire sized 165/82x15 to a few Healey drivers and that the comments have been good.

Do I have it correct that you get total tire diameter by multiplying the first number (tire section) by the second (tire aspect), doubling the product and adding in the wheel diameter? If so this gives me approximately 24.7" for the 175/70 versus 25.6" for the 165/82.
 
Michael, I can not vouch for the math never checked it out,However, the closest tire size to the original specification that also puts a little more meat on the ground for the big Healey is a 185 X 70 X 15 tire.They have been hard to find here of late though.-FWIW---Keoke
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/ubbthreads/images/graemlins/iagree.gif With that patton,if it were a 80 series it might play.---Keoke /ubbthreads/images/graemlins/driving.gif
 
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I have never heard of a modern tire with anything not divisible by 5 where the 82 is... Also cannot find information on Gillett tires on the web.

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Neither have I but that is what Alan told me--82.
They are shown on his site but nowhere else that I can find.
 
/ubbthreads/images/graemlins/savewave.gif
Perhaps this is somthing that the vendor had made up to address his client's needs and we just havent heard about it too much yet we will see.-Fwiw---Keoke
 
When tires were first given metric (instead of inches) sizes the common sidewall ratio was 82% of the nominal treadwidth, but was unstated, so a 165/15 was a 165/82x15 in modern terminology. At least that's what I have read.
Your method for calculating diameter is correct, though usually approximate. If you look at the specs on Tire Rack's website or different manufacturers you will see minor variations in diameter and other specs for tires nominally of the same size. Compare revolutions per mile or
cross section for examples of variations, even within the products of one manufacturer.
Simon.
 
FYI, I see Tires Unlimited still lists Sprint + Vredesteins in the 165R15 size for $66 each.

https://www.tiresunlimited.com/vred_sprint.htm

Awhile back I replaced a set of Firestones with some Vredstein Sprint +. They handle great, look great, and are quiet, but the sidewall seems to be a little stiffer and the ride a little harsher. Gary
 
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