We have recently come accross a situation with Ferrari 275 GTB where some cars were unable to fit the 205VR14 Michelin XWX which of course seemed strange as this is pretty much accepted to be the tyre for that car. When you see a 275 fitting the 205/70VR14 Michelin XWX you can see the difference because the wheel arches seem quite empty. the difference in diameter is 42mm (1 5/8 inches). I now think that the early cars were fitted with a 185R14 tyre. does anybody know for definate what these early cars fitted. i would also be interested to know what make of tyre they fitted.