When I ran my winter (17") wheels on my GTI, I noticed a slight improvement in comfort. Road noise is of course, mostly influenced by the road surface quality (or lack of) and the tyre tread/type.
When I bought my GTI, it had sh!tty budget tyres on the front, which made some racket. When I changed them for Eagle F1's, the noise was noticeably reduced when doing motorway speeds
![happy2 :happy2:](https://www.mk5golfgti.co.uk/forum/Smileys/newsmileys/happy2.gif)