255/40/18s or 255/35/18s for a Audi TT 2007 ?
Hi there :)
When it comes to changing tyre size, we recommend you to check it with your car center.
However you could use this calculator to know if the new size is allowed. It seems that 245/40/18s works http://www.etyres.co.uk/tyre-size-calculator
The rezulteo Team