im a new member, thankgod i found this site, it was almost impossible for me to get the 35x12.5x18 BFG mud terrain, i finally get the 17x35x12.5 with a new sets of wheels, so whats the diference on the driving on a 17 instead of a 18"?, from my point of view the performance onsand ad mud got to be the same.
by the way if u wanna see my fx4 here is the url, thx!!
https://www.f150online.com/galleries....cfm?gnum=6125

 

The performance will be almost identical. The shorter sidewall of the 18's may handle just a tiny bit better on the highway but 99.9% of drivers will never notice.

 

I doubt you would notice much of a difference.

I think 17" is the better of the two sizes anyway, you have alot more options with that size (in the future that may change though...alot more off-road tires are coming out for larger wheel sizes).