I have an 08 F250 6.4 with I believe 17 x 7.5 stock wheels. Could I put 16's on it without modifying anything? I can get nice 16 tires for about a $100 less then 17's and with the rate these big trucks chew through tires, it would pay itself off after one set. Thanks.

 

I would not do that, rather get a set of good tires for the truck. I run Coopers and they lasted well over 45K. Good for an agressive off road tire.

Your speedo would be off though with 16's that should be it.

You'll look like sissy tires in the wheel wells.

 

Supposedly, anything under 17" dia will hit the caliper (I have not confirmed this though).