(S) wheel & tyre sizes (again probably)

hi all.
I couldn't find a thread on this subject , although there probably is one.

I had a hell of a job ordering a set of alloys today as no one could decide what the pcd of the wheels were (local fiat dealers parts department answer "i'm not quite sure" was well worth the call) . After a few telephone calls and telling them that 100 pcd was correct i finaly settled on a set of 17" OZ superturismo gt's.

I wonder if anyone could tell me what the letters ET followed by 2 numbers mean, i take it this is the ofset and what should the number be for my GP. any advise would be appreciated.

It's in the handbook

thanks will have a look tomorrow when i have chance. did have a quick glance through but must have missed it.

205/45-R17

Or you can go for 225/45-R17 on the back and 205/45-R17 on front.
This will give a wider stance from the back and will look the dogs.

I have gone for 205/40-17s for the moment as they were wot were suplied with the wheels when i ordered them, but will keep your sugestion in mind for future (wish i had thought of it before).....thanks