What are the largest tires I can put on my Miata?...rims 14x6, tires P18560R14?

Question

Looking to widen only

Answer 1

if you want to increase the diameter of the tires then there is a simple rule. +1, -1, +1

Example:

185 60 R14
195 50 R15
205 40 R16

That way the overall dimension of the tire stays the same and it will not screw up your speedometer. If you are looking for a larger 14" tire then look at the tag on the vehicle with the tire sizes or check your owners manual.