Is there any mechanical reason why I should not replace my 18 wheels with 17 inch for the winter as they would fit my current winter tyres which are 225.45 17 Goodyear generation 1.  The price of 18 inch tyres is very high at about £170 each. Could it be cheaper to buy new alloys instead

9 minutes ago, Channel said:

Is there any mechanical reason why I should not replace my 18 wheels with 17 inch for the winter as they would fit my current winter tyres which are 225.45 17 Goodyear generation 1.  The price of 18 inch tyres is very high at about £170 each. Could it be cheaper to buy new alloys instead

No reason at all, but check the diameter of the two tyres.

see my solution below:

 

https://www.briskoda.net/forums/topic/451662-wheels-and-tyres/

 

Edited 31 July, 20187 yr by Agerbundsen

I should have mentioned that it is a 4x4 SEL Karok

Try using this wheel/tyre calculator https://tiresize.com/wheel-offset-calculator/ . It will show you the difference (if any) before & after alternative wheel/tyre combinations.