I have had the same set of eagle alloy wheels and 2 different sets of tires on my truck in the last 6 years. First I had cooper ST tires, all tires held air like a champ for about 2 years , then at about the same time all tires developed a slow leak. After another year of adding air every two weeks or so, I decided to ditch the tires because of the leaking and wet road traction became lousy despite plenty of tread left. Then I had a set of Goodyear duratracs put on the same wheels and all was well, no leaks. 2 years or so of running the duratracs, the leaking started again. Checked and retightened the nut on the TPMS valve stem, valve cores replaced. Still leaking and checked thoroughly for nails, cuts, etc. Just like the cooper STs the duratracs all started leaking about the same time at different rates. So again every 2 weeks I have to add air. one tire only ever needs 2 psi, the other two tires need about 5 psi and the worst offender needs about 10 psi every two weeks. Needless to say I'm getting pretty pissed. These tires have 70 percent tread left. Anyone have a clue where the air is going?