Hi was wondering if i would go with 235 75 16 on my 2002xl7  would they fit with no mods,what would it change on the speedometer,would it damage the tranny thax.

They're a bit big for a stocker.  Will rub the frame and possibly some of the body.

Tranny will probably hunt for gears which isn't good.  Power will feel down.  Keep it out of OD until you're at a sustained 55mph+ speed.

Odometer and speedometer will read inaccurately.  Will read slow where the indicated speed is actually slower than the actual speed.

Hi was wondering if i would go with 235 75 16 on my 2002xl7  would they fit with no mods,what would it change on the speedometer,would it damage the tranny thax.

This is a good site for checking what the speedometer difference would be with different tires:

http://www.miata.net/garage/tirecalc.html

- Andy

You'll want to keep it at 29" max.  235 70 16 is as far as you should go without doing other things, as you'll already start having *very* minor frame rub and possibly some plastic rubbing.  235 75 16 is typically nearly 30":  Definite significant rubbing.