Tires: 1996 ford explorer tires, tirerack com, explorer tires

Question
I have a 1996 Ford Explorer with P235/75R15 tires(placard on door jamb has same #). I was wondering if there would be a problem with buying a used (with real good tread) tire from a friend with the size P235/70R15? Also what is the difference between the 75R15 and 70R15. Iknow the 15 is the rim size what about the P235 and the 70 numbers?

Answer
Pete,

First, you need to read up on tire sizing:

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=46

At the end of the article is a link to Service Description.  Read up on Load Index.

What you are doing is reducing the load carrying capacity and that is exactly the arguement that Firestone presented to Congress.

You DO NOT want to put smaller tires on this vehicle!