I don't know if this has been discussed here or not.

Has anyone noticed that the Japan ist comes with a 185/65/15 tire size as standard versus the US xa with a 185/60/15 tire size as standard? Questions as follows:

1. The 185/65/15 tire size is 3% taller than the 185/60/15. Do you think that the two cars' computers are set differently to compensate for the difference? Is it easy to have a tech change the computer settings if I have a US spec xa and I want to run the Japan spec tire size?

2. Doesn't it seem like the US spec tire size always looks undersized in the xa's wheel well no matter what tire and rim combo is used if the diameter is the US spec? Don't you think that that is still true even if the suspension is lowered?

3. Why do you think there is the difference? Do you think that the US spec is conservative to allow for tire chains or what?

4. Because the 185/65/15 size gears up 3%, do you think that it will be better suited to highway driving by holding the rpms down lower? It seems that some people complain that the rpms at 70 mph are pretty high.

5. Do you think that the TRD lowering springs allow for the Japan spec tire size? In other words, no rubbing with TRD springs and the 185/65/15 tire size?

6. Some people complain about the harshness of the xa's ride. Don't you think that the Japan spec tires would offer a smoother ride since there is more sidewall?

7. Lastly, do you think that there will be braking problems if you used the Japan spec tire size on the xa? Does anyone know if the brake components are the same for the ist and xa?

It seems to me like many other vehicles are set up the same way as I described above. The Toyota Matrix comes to mind.

Any comments are surely welcome.

 

ummmmm, 3% is nothing.