i have the same tyre size in my KIA claasic, the first day i changed them, i had wobbling at around 90KM/h although they were balanced, but still and i knew that the problem is due to the balancing. i live in taxila and know a balancing guy here who has brand new balancing and alignment machines. took the car to him the next day, as i suspected , all tyres needed balancing again.. after that, my car is fine , checked it on high speeds, no issues, apart from that, tyres are very good, soft and good grip. so what i would suggest is check the balancing again from a different shop, most of the time the balancing machines are out of calibration , so acording to the machine your tyres would be balanced but in reality they would'nt be.. hope you understand what am trying to say..