a friend of mine is selling his X5 E70 with

Front: 275/40/20
Rear: 275/40/20
with run flats. he asked me is i wanted the tires before he sells the car. I have now 19'' rims and run flat also. Does it really has a difference in driving ?

When i check on the internet where they sell tires and rims then they all say that rear tires are not same as front tires for the E70,can someone explain to me before i make the decision to change them?


Front: 275/40/20
Rear: 315/35/20