Re: Spedo probs
EF II Fairmonts a good model to get.
I don't think you can buy 215/60R15 tyres??
From new Ford sold them with 15' wheels and 205/65R15 tyres.
There was a very popular 16" wheel option ( XR6 ) which came with 225/50R16 tyres.
Either way changing to 235/45R17 tyres does change the speedo reading by 4/5 of F*** ALL.
By good design or strange coincidence there is less than 1/2 a percent difference in rolling radius between 205/65R15, 225/50R16 and 235/45R17 tyres so your speedo isn't affected by the different wheels and tyres much at all.