I have a question regarding tire psi for and 07 Silverado 1500 hd. My door panel suggests a tire psi for 50 in the front and 80 in the back. This seems insanely high to me and had to buy a pressure gauge that goes up that far. I feel every single crack and pebble on the road. Is there an acceptable level that I can drop the pressure down to, especially for snowy roads, or is this just normal for these types of trucks?