Ford F150 - Advice about getting bigger rims

So my truck is 2wd and has the standard 16in rims. I want to get 18's will this be fine, do i need to raise my truck an inch or two and will my mpg go down or will it help?? Thanks for the advice!

18 inch rims are not a problem. Just make sure you keep around the same circumference and no lift is needed.

alright thanks so much!