Since picking up the New Kia Optima Hybrid in 2012, all the tires lose at least 6 pounds of pressure each month whether the car is moved or not. I have driven it to N.J. two times, 1200 miles one way, and had to put 6 pounds of air into all 4 tires after arriving, the same when returning home. 1200 miles, whether driven in one week or one month. Dealer claims nothing is wrong, tire manufacture removed tires and water checked for leaks, non were found. I was there when tires were checked. The problem is with the interior tire pressure monitor, it is leaking air through valve or stem. Kia and the dealer deny their is a problem, although they have recalled the tire pressure monitors on our 2011 Kia Sorento. As a retired mechanic, I know how low tire pressure is a serious and dangerous problem. Car handling, low fuel economy and accidents will occur if tire pressure is not properly maintained. Most drivers are not aware of low tire pressure until the light on the dash lights up. Several complains to the dealer about the light coming on at 22 pounds pressure was dismissed as within federal limits, My 2011 Sorento came on at 29 pounds every three to four months, normal. At only 31000 miles, this has been the only frustrating complaint.