Wow! That's absurd!So here is the results: Clearly more than 5 mm, more like 8mm
Based on the clearance of ~1.5mm I have with a 200mm wide Road 5GT, for a tyre to have (say) 7.5mm clearance on my bike it would have to be no more than 188mm wide, which is less than the specified section width of 190mm. Furthermore, the maximum in service width for the Angel GT, as posted earlier in this thread, is specified as 203mm.
Don't suppose you can get a measurement of the width across the tyre at its widest point, can you?