Hi there,
I recently experimented after nearly losing control in the wet with standard 135 R13 tyres.
Currently I have 165/50 R14 on the front of my Y10 with no problems and 165/65 R14 at the rear but they are too big and I wouldn't risk carrying passengers.
[Don't ask - they were the only tyres I could scavenge]
So I would suggest a maximum on the Panda of 165/50 R14
To avoid rubbing (minimise really) I have had to fit 5MM Alloy Spacers all round. This necessitated the use of longer bolts.
I used to have a set of 155/50 R13 Alloys and they were probably the best compromise between looks and practicality. Good grip and no issues when carrying passengers. No Spacers were required.
Hope that helps.
Regards,
Martin
Fix It Again Tony!