i had 205/50/15s on 8j alloys on my s12,
there stretched but i know that i could fit 195s on there. main thing is choosing the sidewall height. With 195s the height would have to be at least 55 on a 15 inch rim
Also i did not stretch them any further than what i was using as the camber on the back of the s12(especially lowered ones) ment that the iner edge would wear extremely fast and explode.
If your going to do the mad stretched look you should definately do rear camber correction before you drive it