Does anybody know if i can put the OR wheels.16x7.265/75r16 on my Se 17x7.5 265/65r17 without effecting the speedometer and odometer.the OR,s are 16 and the SE,s are 17.If not I also like the Titan,s wheel which seem the same.17x7.5...

The OR is running on 265/75-16: 31.64" diameter - 657.3 Rev per miles.
The SE is running on 265/65-17: 30.56" diameter - 680.6 Rev per miles.

The standard OR size is 3.4% smaller than the SE. Thus minor effect on the speedo (actual will be slightly slower than speedo reading).

Regards

Yes you can use any wheels made for the Xterra or the frontier on your Xterra. The tire size diffeence is negligable. You won't notive a difference and even then it wouldn't be off far enough for you to notice.