Hi All,
I need help with deciding the right tire sizes for my truck.
I have a 21 F150 XLT - Stock suspension and 18" rims with stock tires.

I recently bought a set of wheels - 20x10 -18mm offset
Will I have any issue with rubbing against the fender well or suspension with 305/55's?

Should I go with a smaller tire?

I plan on adding a leveling kit in the future, but not anytime soon.
Thanks in advance

 

Why you got the 18mm offset, that's way too aggressive with 305 your wheels are going to stick out a lot perhaps by 2-1/2 inch. You already got the wheels so it's too late, and I'd get 305/50R20 instead.