[chaz58]

Bigger isn't always better.

For competition, the important thing is having the tire in its designed operating temperature (typically at least 160, optimium around 200 degrees). naturally you want the alignment and pressure to give you even temperatures across the tread width. You can see why this might be a problem on a miata autocrossing with wide tires - they never get into the tires optimum temperature range. Anything over 195 in a miata is iffy if you are trying to get the tires to heat up quickly.

Keep in mind that a bigger tires doesn't mean a bigger contact patch - it just changes the shape of the patch.

I rotated my 225/255 setup to put the 225's up front (just for kicks). I can't say it really handled any better - I had less turn in grip at lower speeds (autocross like).