S3 wheels weights

Does anybody know the weight of the standard S3 wheels (facelift model)?
I'm looking at getting a second set of wheels with track tyres for track days (cheap second hand ones from an A6) and wanting to know if there is going to be a huge weight sacrifice...
i know the A6 wheels are 8" wide where as my S3 wheels are 7.5" so that is going to add some weight but does anyone have any advice on this?

These on my car now:


Fitting these with track tyres for track days:

Thanks mate.

Yeah i knew those wheels wouldn't be ideal for the track but could get them very very cheap.
Think I might need to hunt for some something lighter and more suitable.