I have Hyundai Xcent September 2014 model and after 40,000 Km has upgraded to 165/70/ R14 - Goodyear Duraplus.
Few Observation:
1. Ride Quality has improved. Pothole, rough roads and speed breaker bumps has smoothened out
2. Steering which was lifeless has now got some meat in it
3. Confidence on taking sharp turns in flyovers or twisting road in speed above 75 has increased. Previously with stock tyres never attempted doing it above 60
4. Initially felt the car has gained some height
This size seems to be an optimum mix so as not to damage the stock rack, pinion, pinion joints and tie-rods.
Completed 5000 kms post upgrade. No issue as of now