Just checking fit. 06 FX4 with front level. Looking at 9 in rim 18 inch with minus 12 offset (4.5 backspace) If I go with Goodrich Ta/Ko in a305 65 18 looks like no problem however they will stick out about 1.3 inches more.

Am I correct on this??

 

They will actually stick out 2.5 inches farther than your stock wheels. It will be a tight fit with the 305/65-18's. You may have to do some trimming.