thank you Sir
Idid not change the alloy on the safe side and stick to 14" and today I got Yokohama A Drive 185/65/14 for 5500 each..its diameter is 23.4 still within the limits
With stock suspension, Vitz fit many tyres from 23.0 to 24.3 inches diameter +/-3%
For others information some of the commonly recommended replacement sizes for Vitz (2003-onwards) I've calculated the diameter in inches.
For 14 inch alloy
175/65/14 = 23.0 inch
185/65/14 = 23.4 inch
195/60/14 = 23.2 inch
205/60/14 = 23.6 inch
165/70/14 = 23.0 inch (Not available easily in Pak, except General/EuroStar)
For 15 inch alloy
185/60/15 = 23.6 inch
195/60/15 = 24.2 inch
195/55/15 = 23.4 inch
205/55/15 = 23.9 inch
205/50/15 = 23.1 inch (for lowering the car most)
For 16 inch alloy
195/50/16 = 23.6 inch
205/50/16 = 24.0 inch
205/45/16 = 23.2 inch (for lowering the car most)
For 17 inch alloy
205/45/17 = 24.3 inch
205/40/17 = 23.5 inch (for lowering the car most)
For 18 inch alloy
215/35/18 = 23.8 inch