225-75-R15
Here's the poop (from "http://www.miata.net/garage/tirecalc.html") . . .
Tire Size Comparison
Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
185/60-15 4.4in 11.9in 23.7in 74.6in 850 0.0%
225/75-15 6.6in 14.1in 28.3in 88.9in 713 19.2%
WORST NEWS: your stock OEM toaster tires turn 512 revolutions/mile; that 225 setup will be wildly different at 443 rev/mile, thus throwing off your speedo/odo BIG time, dude. Sorry : (
Tire Size Comparison
Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
185/60-15 4.4in 11.9in 23.7in 74.6in 850 0.0%
225/75-15 6.6in 14.1in 28.3in 88.9in 713 19.2%
WORST NEWS: your stock OEM toaster tires turn 512 revolutions/mile; that 225 setup will be wildly different at 443 rev/mile, thus throwing off your speedo/odo BIG time, dude. Sorry : (






