Any advantage of R13 tire size?

Answer 1

So-so. There are some advantages to smaller sizes, less weight, smaller physical proportions(vehicle will sit lower) ASO. but there are also disadvantages. A smaller wheel usually give a bumpier ride, as curbs and potholes will become proportionally bigger than for a bigger wheel. Unless the gearbox and axles were made for this size it'll also affect top speed and speedo readings