Urgent space saver question

[Finty]

going to scrappies in the morning to get a 16" steelie to replace the joke of a space saver. I have 18" 11 spoke SRi alloys. My question is would the same wheel bolts be usable on the new steelie as the current alloy?

Also I've worked out that a 195/65/R16 be a suitable spare for a 225/45/R18...sound correct?

[Waterboy]

Thats the correct size, just 0.02 of a centimeter diameter difference so mph will be spot on.

I use this little gem to check sizes:

http://www.kouki.co.uk/utilities/vis...ize-calculator