The 315 is not a good fit on a 10" rim in my opinion. The sidewall is definitely pulled in and I reckon you loose some tread footprint from this. It's an ideal fit on an 11" rim.
These are Yokahama ADVAN 315's on 11" rims
These are Sumitomo 315's on 11" rims. Note the nice straight sidewalls on both tyres.
Cheers