Wheels: Tom wrote via e-mail: “You always say to follow the manufacturer’s guidance regarding tire pressure. On my Buick, I have the door sticker prescribed tires. The door sticker says to inflate to 30 psi. The tire itself says not to inflate beyond 44 psi. I don’t like the disparity and would appreciate some sort of official answer. The 30 psi seems a bit low and it seems like that would be hard on the tire. Thanks for your advice.”
Halderman: I asked a tire engineer this question and he told me that the 44 psi designation represents the maximum pressure and where the maximum load weight carrying is determined. The recommended tire inflation pressure, as stated on the driver’s door placard, is determined after extensive testing by both the vehicle manufacturer and the tire manufacturer. Higher inflations most likely create a smaller footprint area and will change the wear characteristics (not always for the better), but can also reduce braking traction available.
Keep to the door placard inflation pressure. Be sure to check the inflation before the vehicle has been driven and do not let air out of a hot tire or it will be under-inflated when it cools.