My local council decided to neglect roads last winter resulting in my Mondeo Titanium X Saloon requiring 4 replacement wheels (and 2 new tyres) - which were funded by the local council. The replacement wheels arrived in 4 'Ford' labelled boxes along with 5 new (non locking) wheel nuts for each of the 4 wheels. A few weeks later I needed to remove the wheels to check brake pad wear and I was shocked to find that after removing the wheel nuts the wheel fell off the hub. This was not normal as the original wheels had to be given a good hard kick or three even to get them unseated from the hub, even then they were a snug fit onto the 5 wheel studs and were not easy to remove. So I checked out the new wheels and to my astonishment the clearance holes on the new replacement wheels were much larger than the M12 (12mm diameter) wheel studs. Rough measurement showed the clearance holes on the new wheels to be almost 22mm diameter - almost 10mm larger than the wheel stud. I then checked the other 3 wheels and they were the same... I then checked ISO (gloabal industry standard) thread clearance chart to see what the clearane hole diameter for an M12 screw thread should be, and for a fine thread like the wheel stud the clearance hoole should be 13.9 - 14.0mm diameter - much less than the Ford replacement wheels on my car. I then checked the size of the wheel nuts accross the 'flats' - these measured between 18 and 18.5mm which is smaller than the almost 22mm diameter clearance holes on the wheels. Conversely a 22mm diameter clearance hole is the correct size for an M20 screw / wheel stud. There is a small seating flange on each wheel nut but these are not supported by the wheel nut 'body', so all the load of holding the wheel onto the hub is being carried out by the weakest part of the wheel nut. This also means that the strongest part of the wheel nut is not being used - dangerous, or potentially dangerous if larger than normal forces are exerted on the wheel nuts like when cornering hard over imperfect road surfaces. I have taken up my concerns with my local Ford Dealer (Evans Halshaw) and their Service Manager stated that replacement wheels do have one standard clearance hole size so they will fit all Ford vehicles - nothing wrong with the wheel stud clearance holes - according to them. Not satisfied I took up my concerns with Ford UK who responded via customer care dept saying the wheel nuts were the correct size, confirming to me that anything remotely technical is alien to Ford. I have now (twice) requested a Ford Engineering / Quality Assurance contact point and this has so far been refused. It seems either that Ford don't want to know, don't know or are just burying their heads in the sands. With the Mondeo being a globally sold Ford car Model any potential safety issues with wrong wheel clearance hole sizes / wheel nut combinations could have disastrous effects should a wheel come adrift. Has any one else had a simlar problem with replacement alloy wheels, I'd be interested in hearing from you?. I'm still trying to get a 'technical' response from a Ford Engineer or Quality Assurance Engineer? See photo of my replacement wheels attached.