[churchx]

Yes, it's possible with stretch, but as for 9" wide wheels in general case minimum is 235, ideal 245-255, max 265, it might be outside optimum what tire/wheel are designed for. From gains - reduced sidewall flex, from losses - increased chance of tire debeading from rim, risky if happens due high speed/side-g turn, and also slight loss of competitiveness via carrying unnecessary wheel weight. Why they choose to run with 225? Most probably of certain class rules regarding tire limits. Why they keep using heavier wheels and overstretch? Who knows actual reasons. Maybe subjective handling feel change inspiring extra confidence in particular driver due sharper steering feel. Or that wheel needed to clear some specific BBK. Or that is some specific non generic tire used, eg. some race slick that might be used on wider width range. Or they keep using same wheels with different tires depending on weather or class regulations. However, in generic case with generic tires on generic wheels, overstretching imho is not optimal. It may have it's use in past for illegal street racers / drifters using stretching as hack to enhance somewhat handling by reducing sidewall flex of then worse performance tire selection or cheap non performance tire usage due tight budget, but these days with much better tire offering for reasonable prices or better cars/better suspension, imho not needed.