Take a look at the sidewall of your tires...notice there are no arrows. Also look at the symmetry between the tires, notice if you invert them they are the same. I tried this when putting back my OEM 19s after I had my winter wheels on.

 

hrm...ok...maybe I should do a quick rotation of my fronts and rears this weekend... I have 16k miles on my Potenzas and they are starting to show a little wear.

 

Just a little. some here only get 15k and they're gone alrady.

 

hahah well when I mean a little wear...I mean at least half way...Not to the wear bars..but you can tell they aren't new tires