Ok..

I've got 15" rims, tyred are 195/50.

If I were to get say, 16" or 17" rims, what tyre size would I need to keep the circumference the same as the current wheels plus tyres I have? 195/50s come standard for the 2.0.

depends on the wheel width.

To find the rolling radius you need a tyre size calculator.

Have a look at www.tyresave.co.uk - here

I assume you know what offset(s) and PCD will fit....

J.

For std VAG dimension wheels

16" 205/45 16

17" 205/40 17 or 215/40 17

18" 215/35 18

thanks soo much J