Well I just ordered some Shelby flat black CS1 20x11 20x9 rims. I ordered them with 255/35/20 Nt05 up front and 315/35/20 NT05R tires in the back. What life should I expect from my rear tires as i DD my stang 20 miles a day. I race maybe 1 time a month but im hard on my weekend drives around. Still have the option to do the non R nt05 sames size for less $ would they really last that much longer?