I have been an aircraft mechanic for over 22 years and surprisingly this problem occurs on aircraft tires occassionally. I have 2 thoughts on this problem, #1, Each model is thoroughly road-tested and evaluated for any problems. Leaking tires over a short period of time would definitely be noticed by any test driver and evaluator. It is interesting that this problem has never been mentioned in automotive review magazines or on-line evaluation sites. #2, I believe there could be a manufacturing defect or flaw with the 22" wheels. Sometimes during the forging process an edge of the wheel along the bead seat area is rough and not able to seal properly thus causing leaks. Ford obviously does not manufacture this tire and I cannot recall presently the name of the manufacturer. e350 coupe is right on about his explanation of the TPMS. I check my tire pressures once a week and hope I do not have any trouble.