PRESSURE IN TIRES CHANGE...when onstar read the pressure it may have been cold out and you just started the vehicle. Did you check DIC to see what it read before you went to station . Pressure could have gone up as tires heated uppaulfdoig said:OnStar sent monthly report and it said my tire pressure was 31 in all four tires. I went to gas station to add air, and all 4 were 35psi?OO :banghead:[/color]
You are adding 80% Nitrogen to the supposedly 100% Nitrogen gas within the tire. I would go back to the place that put the Nitrogen initially, and ask them to top off the tires - FOR FREE !SoCalSRX said:My tires have nitrogen in them. Is there any downside to topping off with air?