Tires: tires, tirerack com, tire failure

Question
what does the tire size means--example 265.  I am changing tire size from 265-70-17 to 255-70-17.  Do I need to do anything else to the computer.  

Answer
Loreto,

You don't want to be doing this.  This is going down in load carrying capacity and you are increasing your risk of a tire failure.

Try typing "tire calculator" in a search engine.  You want to stay very close to the original diameter, then check to see if the Load Index is the sae or higher for the new tire size you are considering.

Hvaing done this a few times, A P255/75R17 is the right size if you want to go smaller in width.

Plus you ought to look at Tire Rack's tire tech area about tire sizing.

http://www.tirerack.com/tires/tiretech/tiretech.jsp