Do you know what gears you have already?
Code on the door sticker will let you know. The reason I bring this up is that depending on what you have, the tire size could severely affect your acceleration and mpg.
I have 265/75/16 on my 2010 with 3.55 gears. It blows and I lost ~4mpg. I'm going to regear eventually, though.
42= 4.10 Open Diff
45= 3.55 Open Diff
46= 3.73 Open Diff
D2= 4.10 Limited Slip
D4= 3.73 Limited Slip
D5= 3.55 Limited Slip