Speedometer gear Question

A 245/60-15 tire is in the 26 -26.5" range. A 26" tire coupled with a 3.55 gear would be a 36 tooth (red) gear. If you jump up to a 28" tire you would need a 33 tooth (yellow) gear. Any tire size in between would require a gear somewere between the 36 and the 33 tooth gears. Your 32 tooth gear will make the speedo read faster than you are going.

Chuck