I have a 1996 toyota corolla, and recently I blew a tire. Whoever owned the car before me put on 195/50r15 tires instead of the standard 175/65R14s. I've had very little luck finding a spare tire, but i did find a set of 4 on craisglist with rims for $125 (link: Craigslist (http://portland.craigslist.org/wsc/pts/1102488556.html)). I contacted the seller and they are the 4-lug rims, since I know that the tire size works for the car and that they are 4-lug rims, will they fit my car? or are there differences besides # of holes in the rims?

Also, why would the person who owned the car before me switch to a non-standard tire size?

You said you blew a tire... unless you kept driving on it and screwed up the wheel, just replace the tire.

I personally would not buy/use a used tire. You have no idea how old they are. They may have been run at very low or very high pressure and may have been weakened/damaged. There are different bolt patterns for wheels, either measure (diagonally, from center of both studs. It will be in mm) or search online.

There are many reasons to change to a larger rim. People mainly do it for looks; but it helps with cornering a lot, most people just don't need that. My dad's got a corolla, not sure exactly, but I want to say the tires that came on his are 185/55/15. If you're only going one number up or down, adding 5 to the first number and subtracting 5 from the second number keeps you pretty close if you keep the same rim.