Jamesinchamonix

Hi. I’m not exactly an expert on Audi’s...I’ve owned mine for 1/2 day ! But winter tyres ...and my new Audi A6 manual ... Rim size 7.5jx19 rim offset 33 mm tyre size 235/45 rim size 7.5 jx18 rim offset 37mm tyre size 225/50 I’d be amazed if the MMI doesn’t have the ability to input your tyre sizes to correct the speedo, but honestly you are talkin 1-3 % so don’t sweat it. The offset is the key to the wheel clearing the chassis etc. check whether you have ceramic brakes , if so 19” wheels. if not you could go 18” .The advantage is the 225 width . It cuts through the snow better and the price and availability. You will get a better selection.