I have a 2001 FORD F-250 Xcab 4X4. It currently has the original tires, 265/75R16.

I am wanting to increase the size of the tire to improve the look of my truck. I would rather stay away from all types of lifts and am just wanting to get larger tires. I am not completely clueless as to tire sizing and other tire issues but want to plumb the depths of knowledge here at my AR family before I talk to the bubba's at the local tire shops.[:D]

What is the largest size tire that I can safely place on my truck?

Thanks in advance, mi familia!

try www.tirerack.com
i believe they can suggest larger tire sizes

you should be able to fit 32" tires nicely, you could fit 33's but they would rub.

Thanks guys, I knew that I could count on you!

What bumper do you have up front?   If you have a complete front end replacement, you might be able to go up to 315/75 r16.  Keep in mind that the original wheels are 16x7, anything bigger than 285/75 r16 is going to make putting on weights to balance unreliable at best.(stick ons will work, but might get peeled off if you go mudding, at worst could scratch you wheels in the process)  Factory bumpers invade the wheel well quite a bit, but 305/70 r16 are possible, depends how tall she is from ford.  I am not even going to touch brands, but deal with reputable people, and find out what services you are getting after the sale and for how much.  good luck