I recently got my new (used) wheels....17" Motegi's with Kuhmo Ecstsa Supras....the rears are really worn....smooth on the inside, very minimal tread on the outside....every time i come to a stop i hear this whurring noise from the rear of the car....i know they need balancing (slight vibration above 70mph) and im wondering if the noise is from the tires, or my diff? I can also hear it slightly at speed.
By the way, the noise was not present from the initial install....just recent, also it got very cold here in the past week or so.....
Any help would be appreciated...

Thanks,
John