larger wheels...how fast am i going?
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- 25rsfun
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larger wheels...how fast am i going?
i put on some 18'' wheels on my rs and i wanted to know if anyone knew the conversion is for the spedometer with the plus size wheels, and if there is anywhere around to get it calibrated.
- Cereb Daithi
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- WRXWagon2112
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Try the Miata.net tire calculator.
http://www.miata.net/garage/tirecalc.html
Put in your stock tire size and then the new tire size and it will give you the % you are off.
http://www.miata.net/garage/tirecalc.html
Put in your stock tire size and then the new tire size and it will give you the % you are off.
- drwrx
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Those conversions are decent, but they are by no means exact.
Every tire from each manufacturer will have it's own dimensional differences.
For example the diameter of a Bridgestone RE92 205/55 16 is 24.8" and does 837 revs per mile. A Yokohama ES 100 205/55 16 is 25.1" and does 828 revs per mile. The RE 92 also has 11/32" tread depth while the ES 100 only has 9/32." The ES 100 tread width is also 7.5" as opposed to the RE92's tread width of 6.2" while the tread width difference won't throw off your speedo, an extra 1.3" of contact patch pays off in dry traction on the road.
Every tire from each manufacturer will have it's own dimensional differences.
For example the diameter of a Bridgestone RE92 205/55 16 is 24.8" and does 837 revs per mile. A Yokohama ES 100 205/55 16 is 25.1" and does 828 revs per mile. The RE 92 also has 11/32" tread depth while the ES 100 only has 9/32." The ES 100 tread width is also 7.5" as opposed to the RE92's tread width of 6.2" while the tread width difference won't throw off your speedo, an extra 1.3" of contact patch pays off in dry traction on the road.
- Libra Monkee
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Re: larger wheels...how fast am i going?
I know there was I place I went near Fairfax Circle last year after one of my speeding tickets. Can't remember what the name of was though.25rsfun wrote:...if there is anywhere around to get it calibrated.
Libra Monkee- "Helping DCAWD meet its Equal Opportunity requirement since 2006."
- zaxrex
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- drwrx
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The easiest way is to check the diameter of the "stock" tire vs. the 18" tire that you are replacing it with. If your stock tires were 205/55 16 you know the diameter should be around 25" so go with a 225/40 18 tire which average right around 25" in diameter. That would keep your speedo calibration on target.