ookay lets say that they ve technically improved the suspension to keep the body roll at the minimum with improved roll grip. now just see the practical implication of that IMPROVEMENT: the car shudders like anything over a rough patch of road and you feel the texture of the road. now would you term that improvement as practical keeping in view the conditions of our roads??? my point is for a car like city you really need to do something about the comfort. comfort alone is the factor that needs to be improved and the rest is already there because of city's design features. the car will not show sign of body roll as its suspension is already too stiff.
we wont be having this discussion if it was not for city's features that are all kept by default leaving no margins. i have driven last gen city with 16 inches rims and low profile tyres and surprisingly it didnt feel bad. can you do the same with the current city??? i think not if you don't want to ruin the technical marvel of a suspension it has.
just sit and observe a City from the front which has a 1+ tyre size on its stock rims. Even with the stock rims you ll see the sides of the tyres protruding out of the shape of its body.
So my point is: the car (esp. the 1.3 variant) already comes with the biggest tyre size it can handle. if you want to improve comfort then a wider tyre size will do while downgrading to a 14 in size rim. a bigger size will take away the power of the car (esp the auto transmission ones).