OK so here it is at the risk of sounding silly I would appreciate some knowledge. I have a Mk3 Mondeo ghia 155 tdci it's basically a lovely low mileage car with a bit of poke when needed. The alloys on it are ok but I'm coming close to needing a couple of tyres . It's on an 06 plate euro4 it's running on 17 inch rims with 205 50 by 17's but have come across a person selling their 18 inch rims with 4 nearly new tyres from the mk3 ST tdci which is in many ways the same car with a few extra bobs n tassles as mine. Will the ST alloys with 225 40 18's go onto mine that is running on the 205 50 17's without any adapting and changing things? Sorry if this sounds daft but I can basically pick the ST alloys up with 4 near new tyres for less than the price of two decent new tyres.