Mines on nitrogen so next to never ; but I check the psi every other Saturday
Had to put air in two tires last night for the first time myself. Cold and rainy weather is not the best time for the TMPS to go off but glad to have it. The dealer has filled them twice since I've owned my car. Hope info helps.I've never checked mine since I bought the car, since I have TPMS, but I think I'm on nitrogen also. I used to check my pre TPMS Civic Si about every week or two weeks