Has anyone used a 255 45 18 on all four tires will there be any fitment issues

 

Those tires are virtually identical in width and overall diameter to 255/60-15s. I've run the latter on several A-body cars. The rear is no issue. Expect the fronts to rub slightly if you hit a bump with the front wheels turned all the way to one side (for example, if you hit a bump while turning into a driveway). This assumes you have wheels with proper width and offset. I used 15x7 SSII wheels with zero offset. Any non-zero offset will likely increase rubbing. Any additional wheel width may also be a problem, though the shorter sidewalls will mitigate that.