there is a limit on every Japanese domestic car eg. a Nissan 350z uk model can go up to 250k/h and the Japanese has a top speed limited of 180k/h so the Q: is does it make any difference in the gear ratios like there would be a difference between both cars 1st gear top speed
The specs are the same but its a Japanese law for all japanese manufacturers for domestic models to restrict the car to a limited speed of 180kms. Ratios remain the same, its just a speed limiter.
So its just not the Z, any domestic model japanese car is restricted to 180kms. its can be a corolla, civic, soarer, Z350, Lexus, cygnus or Rx8. etc etc