If you look at the tire inflation sticker in the driver's door frame, you'll see that the factory recommended pressure is 35#. However, I feel that it is too soft, and run the tires at 40#, which feels better to me. When towing, I may bump the pressures up to 44# (tire max). The tire inflation monitor system does not monitor air pressure - it watches for a difference in wheel speed. A tire with low pressure will turn faster, and the system will notice that and let you know. However, it is up to you to recalibrate every time you change tire pressure so that system knows what normal is. Read your manual - it will tell you how to do that. If you don't, you could get false warnings.