Hello, just wondered if anyone had fitted bigger sidewall tyres to their scout 16 inch wheels, i.e. 205/55/16 

I know it will have an effect on speedo readings etc but wondered if it was viable to fitting the smaller 15 inch rims ?

Hi, not sure but u find this site handy for wheel size stuff, just put your info in. has a comparason thingy too to check what you hot against what you want with recomendations and clearances, how accurate i don't know!

https://www.wheel-size.com/size/skoda/roomster/

I fitted  a set of Mk2 Fabia 15s with more sidewall to my Scout a few years ago simply for  a little more comfort.