When my stock Michelins wear out I'd like to get a set of the BF Goodrich A/T's. Anyone have these with the 4.6 engine? Do they affect performace? How long do they last? Does going with a little larger tire on the 17" wheel affect performace? Thanks.

 

The only affect on performace will be if you go with a larger size. How much, depends on your powertrain and your OEM size and new tire size.
Also, you can easily get 60,000 miles out of the AT KO's.

 

I've got BFG's on 16" wheels on my FX4,Awesome tire but I got a 5.4

 

It`s an 04 5.4 315 on 17`s
But like wandell said, you should be able to get about 60,000 miles

 

I have a set of 285/75R16 on my 2003 with the 4.6 it does fine I didn't notice a difference in power when I switched from the stock tire to the BFG and the new rims. The last set I had I ran for 71,000 miles and they still looked decent for having that many miles I even kept one for a spare (lol)