Tires: Tire sizes, tire retailer, tirerack com

Question
will a p205 40r17 tire fit the same rim as a p205 50r17 with no complications? And what do the 40 and 50 mean? I was told by a friend that the 40 and 50 are just the width of the tire is that true?

Answer
Katie,

You need to read up on tire sizing and Tire Rack has done a better job than I could:

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=7

I can see you are replacing tires - and since there are some complex issues involved I suggest you consult with a tire retailer to guide you through the process.  The direction you were going was the wrong way.