Max size wheels on a fiesta04?

[Fiesta04]

Hi, I was wondering what are the maximum size wheels I could put on my fiesta 2004? If it's any bigger than 15 inch what tyres would I need for it?

Thanks in advance

[northwestrecovery]

17s 205 40 17 aka fiesta st or 195 45 16 zetec s 18 will go on but tyres will be like elastic bands .