Miata Tyre Size Comparison - changing rims and tyre profiles
Out of interest, had a look at the comparative size ratios using the Miata Tyre Calculator: Tire size calculator
| Specification |
Sidewall |
Radius |
Diameter |
Circumference |
Revs/Km |
Difference |
| 255/55-19 |
140mm |
382mm |
763mm |
2397mm |
417 |
0.0% |
| 265/60-18 |
159mm |
388mm |
775mm |
2435mm |
411 |
1.6% |
Consistent with the info that Diesel provided earlier. The change from the OEM 255/55 - 19" rims to the new 18" rims with 265/60 profile AT tyres will result in a 1.6% increase on the odometer readings, 19mm extra sidewall [bigsmile1], 12mm overall diameter increase with 6 fewer revolutions of the tyre to cover a km. Interesting... and something to incorporate in IID Tool settings to correct.
Cheers
Naps