I own a completely stock 04 Nissan Xterra. Now my main warranty is up and im ready to break her out a bit more, and im due for tires so first things first. Im looking to up my tire size up some from what is recommended but have been told that it will serously affect my vehicle and its operation. I was told my ABS and other various controls would not act properly and it could do some harm. I understand my speedometer would show a slower speed due to the greater diameter but would my car not function properly or better yet, cause damage? Let me know how you feel/know about this, im split...

as long as all 4 tires match, it won't cause damage.

ABS won't be seriously affected.