Just found this on tinterweb "
Wheel Jargon Offset
Referred to as ET. This is the distance in millimetres from the centre line of the wheel to the surface of it's mounting face. It's not the most simple aspect of wheel fitment to get your head around but basically the smaller the offset, the further out of your arch the wheels will sit. The higher the offset, the further into the arch the wheel will sit.
Understand it now, it states offset for a clio is 35 - 42.
So in laymans terms because the offset is 37 they sit further out from the arches and that will now mean lowering is a problem ?
Not that bothered as wasnt thinking of lowering as yet anyhow, i like the ride as it is ...