Tires: upgrading tire size on ford ranger, ford ranger, discount tire

Question
Hi, I have a 1995 2 wheel 4 cyclinder 2.3 l ford ranger that has 225/70/r14 tires on it and I would like to upgrade to r15 tires because they are easier to find.  Do you know what size r15's I can get away with?  I've tried using multiple online tire size calculators and charts and haven't gotten any of the to work or give me answers.  thanks.
-Aaron

Answer
Aaron,

First, I hope you realize you have to buy wheels to put on 15" tires.

But if you are willing to buy wheels, I suggest you work through a retailer who has done this type of work and knows how.  Both Tire Rack and Discount Tire do this on a regular basis.  

Go to their web sites and they will walk you through the process.